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All the reasons you might be having night sweats – and when to see a doctor

<a href="https://theconversation.com/profiles/siobhan-banks-18473">Siobhan Banks</a>, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> and <a href="https://theconversation.com/profiles/linda-grosser-1461631">Linda Grosser</a>, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> You’ve finished a workout, so you’re hot and drenched with perspiration – but soon you begin to feel cool again. Later, it’s a sweltering summer evening and you’re finding it hard to sleep, so you kick off the covers. Sweating is a normal part of the body’s cooling system, helping to release heat and maintain optimal body temperature. But regularly waking up during the night, soaked through from excessive sweating is not. Night sweats are <a href="https://www.mayoclinic.org/symptoms/night-sweats/basics/definition/sym-20050768">repeated episodes</a> of excessive or intense sweating at night. They are an unpleasant part of life for many people. Many conditions and factors can trigger night sweats by changing the body’s tightly regulated temperature set point, at which the body attempts to maintain its <a href="https://www.tandfonline.com/doi/full/10.4161/temp.29702">core temperature</a>. Some triggers are harmless (a hot bedroom) or even related to positive lifestyle changes (exercise). Others have an underlying cause like menopause, infection, disease or medication. <h2>Temperature control and sweating</h2> The hypothalamus, located in the brain, is part of the <a href="https://www.hormones-australia.org.au/the-endocrine-system/">endocrine system</a> and the temperature control centre for the body. It contains <a href="https://www.statpearls.com/point-of-care/29920#ref_19631766">temperature sensors</a> that receive information from nerve cells (thermoreceptors) located centrally (in the organs) and peripherally in the skin. Thermoreceptors detect changes in body temperature, sending signals back to the hypothalamus. These <a href="https://www.sciencedirect.com/science/article/pii/S1876034111000256">signals</a> will either activate sweating to cool the body or shivering to warm the body. <h2>Hormones and night sweats</h2> Anyone, regardless of age or gender, can experience night sweats. But women experience night sweats more often than men, largely because menopause and associated changing hormone levels are <a href="https://www.tandfonline.com/doi/abs/10.3109/13697137.2011.608596">a leading cause</a>. Approximately 80% of women experience <a href="https://link.springer.com/article/10.1007/s00737-007-0209-5">hot flashes</a> (also called hot flushes) or night sweats after <a href="https://www.menopause.org.au/hp/information-sheets/what-is-menopause">menopause</a> (when periods have ceased for 12 months) and during <a href="https://www.healthdirect.gov.au/perimenopause">perimenopause</a> (the time leading up to it). While both hot flashes and night sweats produce a feeling of overheating, they are different experiences associated with menopause. Hot flashes occur during the day, are transient episodes of flushing and may involve sweating. Night sweats occur at night and involve an intense period of <a href="https://www.proquest.com/docview/2821423865?accountid=14649">sweating</a>. Changing oestrogen levels are thought to impact norepinephrine and serotonin levels, two neurotransmitters that influence <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6459071/#:%7E:text=%5B21%5D%20Estrogens%20stimulate%20the%20production,norepinephrine%20which%20disturbs%20hypothalamic%20thermostat">temperature regulation</a> in the hypothalamus. Hormones also influence night sweats in men, particularly those with low <a href="https://www.healthdirect.gov.au/testosterone">testosterone</a> levels, known as <a href="https://www.hormones-australia.org.au/endocrine-diseases/hypogonadism/">hypogonadism</a>. Around 38% of men aged 45 years or older have low testosterone <a href="https://www.scielo.br/j/ibju/a/RZqqfTn5tY6BFpV6rp3GMxJ/">levels</a> but it can affect men at any age. <h2>Infections, disease and medications</h2> When fighting infection, our body temperature often <a href="https://europepmc.org/article/nbk/nbk562334">rises</a>. This can stimulate sweating to cool and decrease body <a href="https://www.sciencedirect.com/science/article/pii/S1876034111000256">temperature</a>. Minor infections like the common cold can cause night sweats. They are also a symptom of serious infections such as human immunodeficiency virus (HIV) and diseases such as <a href="https://www.aafp.org/pubs/afp/issues/2020/0101/p34.html">Hodgkin’s</a> and <a href="https://link.springer.com/article/10.2165/00002018-200831020-00002">non-Hodgkin’s lymphoma</a>. However, night sweats are rarely the only symptom present. Medications such as selective serotonin reuptake inhibitors (SSRIs), corticosteroids, thyroid hormone replacement and methadone can cause night sweats. These medications affect parts of the <a href="https://link.springer.com/article/10.2165/00002018-200831020-00002">brain</a> and neurotransmitters that control and stimulate sweating. Regular alcohol (particularly alcohol dependence) and recreational drug use can also <a href="https://link.springer.com/article/10.2165/00002018-200831020-00002">increase the risk</a> of night sweats. <h2>Stress, snoring and strenuous exercise</h2> Night sweats are commonly reported by people with <a href="https://karger.com/spp/article-abstract/26/2/92/295722/Psychological-Sweating-A-Systematic-Review-Focused?redirectedFrom=fulltext">anxiety</a>. Psychological stress activates the body’s fight or flight system releasing neurotransmitters that increase heart rate, respiration, and blood pressure. This causes the body to heat up, at which point it starts sweating to cool the body back down. Night sweats may also increase anxiety, causing more sweating which in turn leads to less sleep and more anxiety. If anxiety causes night sweats and this causes distress, it’s best to get up, move around and engage in a <a href="https://www.calmclinic.com/anxiety/symptoms/night-sweats">calming routine</a>, preferably in a dark or dimly lit room. Night sweats have similarly been connected with sleep disorders like <a href="https://www.healthdirect.gov.au/obstructive-sleep-apnoea">obstructive sleep apnoea</a>, where the airway is repeatedly blocked during sleep and there is loud snoring. About one third of people with obstructive sleep apnoea regularly <a href="https://link.springer.com/article/10.1007/s11325-011-0502-4">experience night sweats</a>. The exact cause is undetermined but research shows it is linked with low blood oxygen levels (<a href="https://link.springer.com/article/10.1007/s11325-022-02701-3">hypoxemia</a>) and/or <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2869.2009.00743.x">high blood pressure</a>. People can experience night sweats after high-intensity workouts. Vigorous exercise can stimulate the thyroid, <a href="https://www.ncbi.nlm.nih.gov/books/NBK500006/#:%7E:text=Thyroid%20hormone%20increases%20the%20basal,respiration%20rate%2C%20and%20body%20temperature">increasing basal metabolic rate</a> and body temperature for up to <a href="https://journals.lww.com/acsm-msse/Fulltext/2011/09000/A_45_Minute_Vigorous_Exercise_Bout_Increases.6.aspx">14 hours post exercise</a>. So night sweats can occur even after a vigorous morning workout. Night sweats can indicate overtraining and/or under-fuelling. If not enough calories are consumed to support the increase in training, blood sugar could drop and you could experience <a href="https://www.aafp.org/pubs/afp/issues/2003/0301/p1019.pdf">hypoglycaemia</a>, which can cause night sweats. <h2>When to seek help and 5 things to try</h2> There are <a href="https://www.aafp.org/pubs/afp/issues/2020/1001/p427.html">numerous</a> health conditions and medications that can cause night sweats and interfere with sleep. If night sweats are regular, distressing, interfere with sleep or are accompanied by symptoms such as fatigue or weight loss (not related to lifestyle or diet changes) talk to a doctor to help determine the cause. They might suggest alternative medications to any you’re taking or recommend tests or investigations. In the meantime, you can try the following ideas: 1. sleep in a cool room and use a fan if needed 2. don’t overdress for bed. Wear breathable cotton or linen pyjamas 3. choose lightweight bedding you can kick off. Avoid synthetic fibres and flannel bedding 4. consider a cooling mattress or pillow and avoid those (such as foam ones) that can limit airflow 5. avoid spicy foods, caffeine or alcohol before bed.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/211436/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/siobhan-banks-18473">Siobhan Banks</a>, Research professor, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> and <a href="https://theconversation.com/profiles/linda-grosser-1461631">Linda Grosser</a>, , <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> Image credits: Getty Images This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/all-the-reasons-you-might-be-having-night-sweats-and-when-to-see-a-doctor-211436">original article</a>.

Body

Hot flushes, night sweats, brain fog? Here’s what we know about phytoestrogens for menopausal symptoms

<a href="https://theconversation.com/profiles/caroline-gurvich-473295">Caroline Gurvich</a>, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a>; <a href="https://theconversation.com/profiles/jane-varney-963066">Jane Varney</a>, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a>, and <a href="https://theconversation.com/profiles/jayashri-kulkarni-185">Jayashri Kulkarni</a>, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a> While some women glide through menopause, <a href="https://pubmed.ncbi.nlm.nih.gov/26271251/">more than 85%</a> experience one or more unpleasant symptoms, which can impact their physical and mental health, daily activities and quality of life. Hot flushes and night sweats are the most common of these, affecting <a href="https://pubmed.ncbi.nlm.nih.gov/29393299/">75% of women</a> and the symptom for which most women seek treatment. Others include changes in weight and body composition, skin changes, poor sleep, headaches, joint pain, vaginal dryness, depression and brain fog. While menopause hormone therapy is the most effective treatment for menopausal symptoms, it is sometimes not recommended (such as following breast cancer, as there is conflicting evidence about the safety of menopause hormone therapy following breast cancer) or avoided by people, who may seek non-hormonal therapies to manage symptoms. In Australia it is estimated <a href="https://pubmed.ncbi.nlm.nih.gov/26224187/">more than one-third</a> of women seek complementary or alternative medicines to manage menopausal symptoms. But do they work? Or are they a waste of time and considerable amounts of money? <h2>What’s on the market?</h2> The <a href="https://pubmed.ncbi.nlm.nih.gov/30868921/">complementary or alternative interventions</a> for menopausal symptoms are almost as varied as the symptoms themselves. They include everything from mind-body practices (hypnosis, cognitive behavioural therapy and meditation) to alternative medicine approaches (traditional Chinese medicine and acupuncture) and natural products (herbal and dietary supplements). There is some evidence to support the use of <a href="https://pubmed.ncbi.nlm.nih.gov/23435026/">hypnosis</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/22336748/">cognitive behaviour therapy</a> for the treatment of hot flushes. Indeed these therapies are recommended in <a href="https://www1.racgp.org.au/getattachment/bfaa5918-ddc4-4bcb-93cc-d3d956c1bbfd/Making-choices-at-menopause.aspx">clinical treatment guidelines</a>. But there is less certainty around the benefit of other commonly used complementary and alternative medicines, particularly nutritional supplements. The most popular <a href="https://pubmed.ncbi.nlm.nih.gov/26224187/">nutritional supplements</a> for hot flushes are phytoestrogens (or plant estrogens). This trend has been driven in part by <a href="https://www.dailymail.co.uk/femail/article-11915645/HRT-not-supplement-created-experts-women-RAVING-effects.html">supplement companies</a> that promote such agents as a safer or more natural alternative to hormone therapy. <h2>What are phytoestrogens?</h2> Phytoestrogens are plant-derived substances that can show oestrogen-like activity when ingested. There are numerous types including isoflavones, coumestans and lignans. These can be consumed in the form of food (from whole soybeans, soy-based foods such as tofu and soy milk, legumes, wholegrains, flaxseeds, fruits and vegetables) and in commercially produced supplements. In the latter category, extracts from soy and red clover yield isoflavones and flaxseed gives us lignans. Because declining oestrogen levels drive menopausal symptoms, the theory is that consuming a “natural”, plant-based substance that acts like oestrogen will provide relief. <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528788/original/file-20230529-17-mh3zlk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="Soy-rich foods on a table: edamame, soy milk, soy sauce" /></a><figcaption>Phytoestrogens can be consumed in foods like tofu or soy milk. <a class="source" href="https://www.shutterstock.com/image-photo/soy-bean-tofu-other-products-187030769">Shutterstock</a></figcaption></figure> <h2>What does the evidence say?</h2> In the case of isoflavones, initial support came from <a href="https://pubmed.ncbi.nlm.nih.gov/23562010/">epidemiological data</a> showing <a href="https://pubmed.ncbi.nlm.nih.gov/15919681/">women in Asian countries</a>, consuming a traditional, phytoestrogen-rich diet (that is, one including tofu, miso and fermented or boiled soybeans), experienced fewer menopausal symptoms than women in Western countries. However, several factors may influence the effect of dietary phytoestrogens on menopausal symptoms. This includes gut microbiota, with research showing only around <a href="https://pubmed.ncbi.nlm.nih.gov/15919681/">30% of women</a> from Western populations possess the gut microbiota needed to convert isoflavones to their active form, known as equol, compared to an estimated 50–60% of menopausal women from Japanese populations. Circulating oestrogen levels (which drop considerably during menopause) and the <a href="https://academic.oup.com/humupd/article/11/5/495/605995">duration of soy intake</a> (longer-term intake being more favourable) may also influence the effect of dietary phytoestrogens on menopausal symptoms. Overall, evidence regarding the benefit of phytoestrogens for hot flushes is fairly mixed. A <a href="https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001395.pub4/full">Cochrane review</a> synthesised study results and failed to find conclusive evidence phytoestrogens, in food or supplement form, reduced the frequency or severity of hot flushes or night sweats in perimenopausal or postmenopausal women. The review did note genistein extracts (an isoflavone found in soy and fava beans) may reduce the number of hot flushes experienced by symptomatic, postmenopausal women, though to a lesser extent than hormone therapy. Another <a href="https://pubmed.ncbi.nlm.nih.gov/36253903/">recent study</a> showed marked reductions in hot flushes in women following a low fat, vegan diet supplemented with daily soybeans. However, it was questioned whether concurrent weight loss contributed to this benefit. In Australia, <a href="https://ranzcog.edu.au/wp-content/uploads/2022/05/Managing-menopausal-symptoms.pdf">clinical guidelines</a> do not endorse the routine use of phytoestrogens. <a href="https://www.nice.org.uk/guidance/ng23/chapter/Recommendations#managing-short-term-menopausal-symptoms">Guidelines for the United Kingdom</a> note some support for the benefit of isoflavones, but highlight multiple preparations are available, their safety is uncertain and interactions with other medicines have been reported. <h2>Can phytoestrogens help the psychological symptoms of menopause?</h2> Less research has explored whether phytoestrogens improve psychological symptoms of menopause, such as depression, anxiety and <a href="https://theconversation.com/brain-fog-during-menopause-is-real-it-can-disrupt-womens-work-and-spark-dementia-fears-173150">brain fog</a>. A recent systematic review and <a href="https://pubmed.ncbi.nlm.nih.gov/33987926/">meta-analysis</a> found phytoestrogens reduce depression in post- but not perimenopausal women. Whereas a more <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9022873/">recent clinical trial</a> failed to find an improvement. Some research suggests phytoestrogens may reduce the <a href="https://www.sciencedirect.com/science/article/pii/S0960076015301254?via=ihub">risk of dementia</a>, but there are no conclusive findings regarding their effect on menopausal brain fog. <h2>The bottom line</h2> At present there is uncertainty about the benefit of phytoestrogens for menopause symptoms. If you do wish to see if they might work for you, start by including more phytoestrogen-rich foods in your diet. Examples include tempeh, soybeans, tofu, miso, soy milk (from whole soybeans), oats, barley, quinoa, flaxseeds, sesame seeds, sunflower seeds, almonds, chickpeas, lentils, red kidney beans and alfalfa. Try including one to two serves per day for around three months and monitor symptoms. These are nutritious and good for overall health, irrespective of the effects on menopausal symptoms. Before you trial any supplements, discuss them first with your doctor (especially if you have a history of breast cancer), monitor your symptoms for around three months, and if there’s no improvement, stop taking them.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/204801/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/caroline-gurvich-473295">Caroline Gurvich</a>, Associate Professor and Clinical Neuropsychologist, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a>; <a href="https://theconversation.com/profiles/jane-varney-963066">Jane Varney</a>, Senior Research Dietitian in the Department of Gastroenterology, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a>, and <a href="https://theconversation.com/profiles/jayashri-kulkarni-185">Jayashri Kulkarni</a>, Professor of Psychiatry, <a href="https://theconversation.com/institutions/monash-university-1065">Monash University</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/hot-flushes-night-sweats-brain-fog-heres-what-we-know-about-phytoestrogens-for-menopausal-symptoms-204801">original article</a>. Images: Getty

Body

Producing electricity from your sweat might be key to next wearable technology

Imagine a world where the smart watch on your wrist never ran out of charge, because it used your sweat to power itself. It sounds like science fiction but researchers have figured out how to engineer a <a href="https://cosmosmagazine.com/science/biology/bacterial-biofilm/" target="_blank" rel="noreferrer noopener">bacterial biofilm</a> to be able to produce continuous <a href="https://cosmosmagazine.com/science/electricity-from-sweaty-fingertips/">electricity fr</a><a href="https://cosmosmagazine.com/science/electricity-from-sweaty-fingertips/" target="_blank" rel="noreferrer noopener">o</a><a href="https://cosmosmagazine.com/science/electricity-from-sweaty-fingertips/">m perspiration</a>. They can harvest energy in evaporation and convert it to electricity which could revolutionise wearable electronic devices from personal medical sensors to electronics. The science is in a <a href="https://www.nature.com/articles/s41467-022-32105-6#ref-CR7" target="_blank" rel="noreferrer noopener">new study</a> published in Nature Communications. “The limiting factor of wearable electronics has always been the power supply,” says senior author Jun Yoa, professor of electrical and computer engineering at the University of Massachusetts Amherst (UMass), in the US. “Batteries run down and have to be changed or charged. They are also bulky, heavy, and uncomfortable.” But the surface of our skin is constantly moist with sweat, so a small, thin, clear and flexible biofilm worn like a Band-Aid could provide a much more convenient alternative. The biofilm is made up of a sheet of bacterial cells approximately 40 micrometres thick or about the thickness of a sheet of paper. It’s made up a genetically engineered version of the bacteria Geobacter sulfurreducens to be exact. G. sulfurreducens is a microorganism known to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209890/#:~:text=Interestingly%2C%20Geobacter%20sulfurreducens%20also%20called,electron%20transfer%20through%20the%20biofilms." target="_blank" rel="noreferrer noopener">produce electricity</a> and has been used previously in “<a href="https://www.nature.com/articles/s41579-019-0173-x" target="_blank" rel="noreferrer noopener">microbial fuel cells</a>”. These require the bacteria to be alive, necessitating proper care and constant feeding, but this new biofilm can work continuously because the bacteria are already dead. “It’s much more efficient,” says senior author Derek Lovley, distinguished professor of Microbiology at UMass Amherst. “We’ve simplified the process of generating electricity by radically cutting back on the amount of processing needed. “We sustainably grow the cells in a biofilm, and then use that agglomeration of cells. This cuts the energy inputs, makes everything simpler and widens the potential applications.” The process relies on evaporation-based electricity production – the <a href="https://www.nature.com/articles/s41565-018-0228-6" target="_blank" rel="noreferrer noopener">hydrovoltaic effect</a>. Water flow is driven by evaporation between the solid biofilm and the liquid water, which drives the transport of electrical charges to generate an electrical current. G. sulfurreducens colonies are grown in thin mats which are harvested and then have small circuits etched into them using a laser. Then they are sandwiched between mesh electrodes and finally sealed in a soft, sticky, breathable polymer which can be applied directly onto the skin without irritation. Initially, the researchers tested it by placing the device directly on a water surface, which produced approximately 0.45 volts of electricity continuously. When worn on sweaty skin it produced power for 18 hours, and even non-sweating skin generated a substantial electric output – indicating that the continuous low-level secretion of moisture from the skin is enough to drive the effect. “Our next step is to increase the size of our films to power more sophisticated skin-wearable electronics,” concludes Yao. The team aim to one day be able to power not only single devices, but entire electronic systems, using this biofilm. And because microorganisms can be mass produced with renewable feedstocks, it’s an exciting alternative for producing renewable materials for clean energy powered devices. <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=200509&title=Producing+electricity+from+your+sweat+might+be+key+to+next+wearable+technology" width="1" height="1" /> <div id="contributors"> <a href="https://cosmosmagazine.com/technology/electricity-from-sweat-biofilm/" target="_blank" rel="noopener">This article</a> was originally published on <a href="https://cosmosmagazine.com" target="_blank" rel="noopener">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/imma-perfetto" target="_blank" rel="noopener">Imma Perfetto</a>. Imma Perfetto is a science writer at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide. Image: Liu et al., doi.org/10.1038/s41467-022-32105-6 </div>

Technology

What your sweat says about you

Here is what your sweat is telling you about your health. You’re giving off good vibes If you smile while you sweat, those around you smile too. At least, that’s what one Dutch study suggests. For the experiment, 36 women smelled sweat samples from 12 men who had watched videos meant to either scare them or make them happy. When a woman took a whiff of a scared guy’s samples, she was more likely to make a facial expression resembling fear. When she smelled the happy guy’s sweat, she was more likely to smile. You’re depressed In healthy people, environmental changes – things that make us scared, stressed, happy, or nervous – have an impact on both the volume and odour of sweat. But when a person is depressed, that response to stimuli declines. One German-Swedish study found that this reduced response was present in up to 97 percent of depressed patients who later committed suicide. “It was probably the case that certain nerve cells in the hippocampus are damaged by depression and negative stress,” Lars-Hakan Thorell, one of the researchers behind the study, said in a press release. “A depressed person has a biological inability to care about the surroundings, while a healthy person continues to react.” Your fitness goals are on track If you break a sweat earlier in a workout than usual, it doesn’t indicate that your endurance has fallen behind. In fact, it should signal the exact opposite. In one 2010 study, researchers found that fitter people not only tend to sweat at a greater volume, but they also start sweating sooner. “A high fitness level allows you to exercise at a higher workload, which generates more heat, which in turn leads to more sweat,” Craig Crandall, PhD, a professor of internal medicine, told Time.com. You’re overcoming an illness Think your partner smells a bit off this week? They might just be sick. One Psychological Science study found that healthy people are able to detect the amped-up immune system of someone fighting an infection. The results suggest that smell is an important warning signal against contagious illnesses. Written by Juliana LaBianca. This article first appeared in <a rel="noopener" href="https://www.readersdigest.com.au/healthsmart/9-things-your-sweat-says-about-your-health" target="_blank">Reader’s Digest</a><a rel="noopener" href="https://www.readersdigest.co.nz/healthsmart/9-things-your-sweat-says-about-your-health" target="_blank">.</a> For more of what you love from the world’s best-loved magazine, <a href="http://readersdigest.innovations.co.nz/c/readersdigestemailsubscribe?utm_source=over60&utm_medium=articles&utm_campaign=RDSUB&keycode=WRN93V">here’s our best subscription offer.</a> <img style="width: 100px !important; height: 100px !important;" src="https://oversixtydev.blob.core.windows.net/media/7820640/1.png" alt="" data-udi="umb://media/f30947086c8e47b89cb076eb5bb9b3e2" />

Beauty & Style

5 things your sweat says about your health

Here is what your sweat could be saying about your health. 1. You need more sodium Salty sweat is your body’s request for more sodium. If your sweat stings your eyes, burns in an open cut, leaves a gritty feeling on your skin, or produces white streaks on your face or clothes, it could be your cue to amp up your sodium intake. Add salt to foods such as eggs, vegetables, or meats, and drink a sports drink rather than plain water when you exercise, advises Runner’s World. 2. You might need to kick the coffee habit Too much coffee could be to blame for the sweat circles that appear on your morning commute. “Coffee increases perspiration in two ways,” Liz Lyster, MD, told Huffington Post. “First, caffeine stimulates the central nervous system, activating sweat glands so the more caffeine you have, the more you sweat. Secondly, the heat from the drink itself can make your body feel hot enough to sweat.” If you can’t kick your coffee habit completely, opt for iced or decaf. 3. You’re applying antiperspirant at the wrong time “Antiperspirants are most effective when applied to very dry skin,” David Pariser, MD, founding member and secretary of the International Hyperhidrosis Society, told Woman’s Day. “If you apply them in the morning right before you head out, or right after you get out of the shower, you’ll likely already be sweating or have wet underarms. If the skin’s surface is wet, the chemical reaction that forms from the aluminium [in the antiperspirant] will happen on the surface of the skin instead of in the pores, preventing the sweat glands from getting blocked.” Even if you’re a morning shower taker, use antiperspirant at night before bed. When applied to totally dry skin, the product can last for a few days. Post-shower, apply a deodorant for fragrance and you’ll be good to go. 4. You’re scared A US military experiment suggests that people can literally smell fear. For the study, researchers collected sweat samples from 20 novice skydivers before and during their first tandem jump, and then again as they ran on a treadmill for a similar duration of time. Volunteers in brain scanners were asked to take a whiff of each sample. The brain regions associated with fear were more active when the volunteers sniffed the skydiving sample than the treadmill sample. The results make sense from an evolutionary standpoint – one person’s fear pheromone would alert those around him that danger is in the air. 5. You’re overcoming an illness Think your partner smells a bit off this week? They might just be sick. One Psychological Science study found that healthy people are able to detect the amped-up immune system of someone fighting an infection. The results suggest that smell is an important warning signal against contagious illnesses. Written by Juliana LaBianca. This article first appeared in <a rel="noopener" href="https://www.readersdigest.co.nz/healthsmart/9-things-your-sweat-says-about-your-health" target="_blank">Reader’s Digest</a><a rel="noopener" href="https://www.readersdigest.co.nz/healthsmart/9-things-your-sweat-says-about-your-health" target="_blank">.</a> For more of what you love from the world’s best-loved magazine, <a rel="noopener" href="http://readersdigest.innovations.co.nz/c/readersdigestemailsubscribe?utm_source=over60&utm_medium=articles&utm_campaign=RDSUB&keycode=WRN93V" target="_blank">here’s our best subscription offer.</a> <img style="width: 100px !important; height: 100px !important;" src="https://oversixtydev.blob.core.windows.net/media/7820640/1.png" alt="" data-udi="umb://media/f30947086c8e47b89cb076eb5bb9b3e2" />

Beauty & Style

Why do I sweat so much?

If you’re hot and sticky even before your daily commute, you might ask why you sweat so much. Sweating is usually the body’s way of stopping you overheating. But for some people, sweating becomes a problem. Either they sweat for no obvious reason or (as <a href="https://www.theatlantic.com/health/archive/2019/11/prince-andrew-says-he-once-didnt-sweat-is-that-possible/602227/">Prince Andrew admitted last year</a>) not at all. So why do some people sweat more than others? And what can you do about excess sweating? Remind me again, why do we sweat? Humans need to regulate their internal body temperature to keep it constant, even when the environmental temperature rises, perhaps on a hot day, sitting in a hot-tub or running for the bus. That’s because a rise in internal body temperature can lead to our organs overheating, fatigue, heat exhaustion and heat stroke. Preventing severe heat gain requires a careful balance between the heat our body produces (from everyday metabolism), heat from the environment and the heat our body loses. Our bodies are well-designed for this. We have special temperature sensors in our skin and central nervous system (brain and spinal cord) that send signals to the body’s thermostat in the brain to alert it to increases in body temperature. The body’s largest organ, the skin, is also designed to remove heat from the body. The most noticeable way is losing heat via evaporating sweat. How does sweating cool us down? When our skin or core body temperature rises sufficiently, the thermostat in the brain sends impulses via our central nervous system to increase blood flow to the skin. The thermostat also activates the sweat glands. Our sweat glands release droplets onto our skin that become vapour when the blood flowing through the skin passes underneath. As the sweat vaporises, energy (in the form of heat) passes into the environment, cooling the blood. This cooled blood gets circulated back to the heart and brain, and cools our core body temperature. This is why a day in the sun can feel so draining. Your body is working much harder and using much more energy to keep you cool. By preventing our organs from overheating, sweat not only keeps us healthy, it also allows us to enjoy (or tolerate) the hot Australian summer. So it’s important to stay hydrated on a hot day so your body can produce and replace the volume of sweat necessary to keep you cool. OK, but why do I sweat so much? You might find yourself sweating more or less than usual for a number of reasons, other than it being a hot day. Exercise Exercise improves our ability to produce sweat and keep cool. People who exercise regularly (particularly in the heat) can <a href="https://journals.physiology.org/doi/full/10.1152/japplphysiol.00495.2010">produce more sweat</a> during exercise. This helps our bodies perform longer, with less physiological strain. So many of the Australian Olympic athletes will undergo a period of heat acclimatisation in the lead up to Tokyo 2020. Stress Ever notice you become sweaty when you are stressed? A different type of sweat gland, the <a href="https://www.mayoclinic.org/diseases-conditions/hyperhidrosis/multimedia/sweat-glands/img-20007980">apocrine sweat glands</a>, are associated with hair follicles and often respond to <a href="https://www.ncbi.nlm.nih.gov/pubmed/31128655">emotional stress</a>. This type of sweat combines with bacteria on your skin and causes body odour. Menopause <a href="https://www.sciencedirect.com/science/article/abs/pii/S0025619611618119?via%3Dihub">Up to 75% of women</a> experience acute bouts of excessive sweating during menopause, called a hot flush. The <a href="https://physoc.onlinelibrary.wiley.com/doi/epdf/10.1113/JP271456">amount of sweat</a> produced during a two to three minute hot flush can be similar to the amount produced during exercise. Most people think hot flushes are caused by increases in core body temperature. But <a href="https://journals.lww.com/menopausejournal/fulltext/2019/09000/Is_core_temperature_the_trigger_of_a_menopausal.12.aspx">our research</a> suggests this might not be the case. Drinking alcohol Having a couple of drinks with friends may also <a href="https://www.sciencedirect.com/science/article/abs/pii/S0741832905001503?via%3Dihub">increase the sweat response</a>. Alcohol raises your heart rate and causes the blood vessels in your skin to relax and widen. This increases skin redness and your sweat rate, which can actually lead to decreases in body temperature. So, what can I do about it? Excessive sweating (<a href="https://www1.racgp.org.au/newsgp/clinical/what-is-hyperhidrosis">hyperhidrosis</a>) can happen in unusual situations such as in a cooler climate or with seemingly no cause. Although it can be embarrassing and uncomfortable, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4012678/">there are ways to treat it</a>, which you can discuss with your doctor. One option is to use an antiperspirant with aluminium or topical aluminium salts, which blocks the sweat glands from releasing sweat onto the skin. A longer-term option may be <a href="https://www.ncbi.nlm.nih.gov/pubmed/19222249">injecting Botulinum toxin</a> (commonly known as Botox) into the skin. This paralyses the injected area (such as the armpits, hands and feet) and prevents the activation of sweat glands. Other options include using low frequency electrical stimulation (<a href="https://dermnetnz.org/topics/iontophoresis/">iontophoresis</a>), prescription drugs and although controversial, surgery. For menopausal women, <a href="https://www.ncbi.nlm.nih.gov/pubmed/27163520">we have shown</a> closely supervised exercise training can improve temperature regulation, leading to fewer and less severe hot flushes. This training involved 16 weeks of supervised, progressive moderate-intensity aerobic exercise, such as treadmill and cycling exercise, for up to one hour for three to five days a week. In a nutshell In the end, sweating is usually our body’s natural way to protect us from overheating. But if excess sweating is a problem, see your doctor who will outline which treatment options are best for you.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/131135/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/tom-bailey-682494">Tom Bailey</a>, Research Fellow, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/faith-pizzey-954823">Faith Pizzey</a>, PhD Student in Cerebrovascular Physiology, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> This article is republished from <a href="http://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/why-do-i-sweat-so-much-131135">original article</a>.

Body

Prince Andrew claims he 'didn't sweat' – here's the science

Sweating is a controversial topic at the moment. In his <a href="https://www.independent.co.uk/news/uk/home-news/prince-andrew-interview-latest-jeffrey-epstein-bbc-paedophile-a9206661.html">extraordinary</a> recent <a href="https://www.bbc.co.uk/iplayer/episode/m000c1j4/newsnight-prince-andrew-the-epstein-scandal-the-newsnight-interview">BBC interview</a>, Prince Andrew <a href="https://www.youtube.com/watch?v=sE9iJPEuYHE">dismissed</a> some of the <a href="https://www.bbc.co.uk/news/uk-50446065">allegations</a> made against him by Virginia Giuffre (known previously as Virginia Roberts) on the grounds that he couldn’t sweat at the time – she had claimed he had been <a href="https://www.bbc.co.uk/news/uk-50451953">“profusely sweating”</a>. During the interview, Prince Andrew, who has <a href="https://www.bbc.co.uk/news/uk-50446065">categorically denied</a> all of the claims against him, said: <blockquote> I didn’t sweat at the time because I had suffered what I would describe as an overdose of adrenaline in the Falklands War, when I was shot at … it was almost impossible for me to sweat. </blockquote> <iframe width="440" height="260" src="https://www.youtube.com/embed/sE9iJPEuYHE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe> But what makes us sweat, why do we do it – and can some conditions prevent us from doing it at all? The human body is an amazing entity and responds to thousands of internal and external signals every day. These responses enable us to survive in rapidly changing conditions. The skin is the largest and heaviest organ of the human body. It is calculated to <a href="https://www.sciencedirect.com/science/article/pii/S0022202X15503679">weigh</a> approximately three to 4.5kg and, over the course of your life, you will lose about <a href="https://pubs.acs.org/doi/full/10.1021/es103894r">35kg</a> of skin. Skin constantly repairs and replaces itself and performs many functions. It protects the body against pathogens, provides insulation, synthesises vitamin D, provides sensation and most importantly regulates temperature. The regulation of temperature is complex. Nerve fibres detect the temperature of whatever is in contact with the skin and relay this information to the brain, which makes a decision about what to do next – take off a jumper or put on a coat. But there are also more primitive and uncontrollable responses. The skin is covered in most places by hair. When cold, the brain causes these hairs to stand on end, trapping a layer of insulating air next to the skin. Conversely, when it’s too hot, the body sweats, producing fluid from the approximately 4m sweat glands in the skin to help heat evaporate away from the body – cooling us down. <h2>What is sweating?</h2> Sweating is the release of a water-like fluid from special glands in the skin to help regulate body temperature. The fluid is approximately 99% water but also <a href="https://academic.oup.com/chemse/article/35/2/101/483325">contains</a> electrolytes, fatty acids, urea (as found in urine) and lactic acid. Many of these chemicals are now being <a href="https://journals.humankinetics.com/view/journals/ijsnem/18/5/article-p457.xml">analysed</a> to detect health and <a href="http://pdfs.semanticscholar.org/3c33/33413c4cb5674f56e3783a9105a6c7a2d773.pdf">hydration</a> levels, and assist in diagnosing diseases such as <a href="https://www.sciencedirect.com/science/article/pii/S0022347608003983">cystic fibrosis</a>. The body is composed of up to 75% water and the loss of as little as 1% of this can cause dehydration. A 10% loss, meanwhile, can lead to life-threatening changes to the body. A sedentary adult loses approximately <a href="https://www.nature.com/articles/ejcn2009111">450ml</a> of water through invisible perspiration a day, while athletes in hot, dry environments can produce <a href="https://www.ncbi.nlm.nih.gov/books/NBK236237/">1,200ml</a> of sweat per hour. Total water loss can often be between two and three litres a day through sweating, breathing and other routes in a sedentary adult. But in warmer climates and with activity, these rates can increase hugely. <h2>How does sweating work?</h2> Sweating is usually initiated by an increase in body temperature from the normal 37C. When the body senses it is getting too hot, an area of the brain called the <a href="https://www.ncbi.nlm.nih.gov/books/NBK507838/">hypothalamus</a> controls the response. It does this through the sympathetic nervous system – also known as the “fight or flight” mechanism, because it also helps us fight for our lives or run away when we’re in danger. In this case, it triggers nervous impulses to release neurotransmitters (chemicals) that activate the sweat glands. The main neurotransmitter involved in controlling sweating is called acetylcholine and its presence causes sweat glands to produce sweat – although a few also respond to a different neurotransmitter called adrenaline. The reason some respond to different neurotransmitters is to do with the receptors they have on their surface. Think of this as a lock and key – only the correct neurotransmitter (key) can fit in the receptor (lock) to cause the sweat gland to function. In stressful situations, cold sweats are usually mediated by adrenaline. This is because the adrenaline causes the blood vessels to narrow and a few sweat glands to become active – producing a drop in skin temperature and a cold sweat. Most temperature-related sweating, however, is controlled by acetylcholine and the presence of adrenaline would not have any consequence on the function of these sweat glands. <h2>Does everyone sweat?</h2> Sweating is normal and just about everyone does it. Some people, however, do it more or less than others. A complete absence of sweating is called anhidrosis. It can occur in particular areas of the body or be global – where more than 80% of the body has no ability to sweat. The causes are usually damage or pathology of the nervous system, or they may be inherited, such as in the case of <a href="https://www.nhs.uk/conditions/sjogrens-syndrome/">Sjogrens Syndrome</a>. Some individuals suffer from hypohidrosis which is a reduction in sweating and can be indicative of dehydration. Regarding Prince Andrew’s claim, an excess or continual exposure to adrenaline is not widely recognised as causing a lack of sweating in humans. However, there is some data in <a href="https://www.ncbi.nlm.nih.gov/pubmed/6359664">horses</a> that has suggested that exposure to extreme temperatures may result in damage to the type of sweat glands that respond to adrenaline. Similarly, the fact that the central nervous system, and parts of it that are linked to controlling the “fight or flight” response system, can also be involved or damaged in psychological trauma, means it is impossible to rule out this possibility without more information. There are a number of reports of individuals who have developed an idiopathic (unexplained) inability to sweat during <a href="https://pdfs.semanticscholar.org/f593/bab5d37b0f21754a17eb9ab28e29b8c231a9.pdf">military</a> and extreme training. At the opposite end of the spectrum is hyperhidrosis, which is excessive sweating. This condition can be systemic (body-wide) or localised. It is known that axillary hyperhidrosis (excessive armpit sweating) affects approximately <a href="https://www.ncbi.nlm.nih.gov/pubmed/15280843">3%</a> of the US population. Interference of tumours and other <a href="https://casereports.bmj.com/content/2013/bcr-2013-009732">pathologies</a> with the central nervous system can result in this symptom. While sweating is seen to have its primary role in reducing body temperature, it is becoming clear that what is contained in sweat is far more interesting. Sweat even appears to be able to convey a person’s emotional state. Women who were exposed to <a href="https://academic.oup.com/chemse/article/31/5/415/395942">sweat samples</a> that were collected from donors who were exhibiting fear while watching videos, for example, performed better in word association tasks than those women who were exposed to sweat which was produced by people watching neutral videos or samples that had no sweat on them at all. The sweat appears to contain a “signal” that suggests the person was undertaking a task that produced a heightened emotional or fearful state. We may never know the truth about Prince Andrew’s sweating, but it’s something we all do and rely on – and researchers will continue to unlock its secrets for years to come.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/127280/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> Written by Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster University. Republished with permission of <a rel="noopener" href="https://theconversation.com/prince-andrew-claims-he-didnt-sweat-heres-the-science-127280" target="_blank">The Conversation</a>.

Body

“I don’t drink or sweat”: Prince Andrew denies allegations from Epstein’s “sex slave” Virginia Roberts

In a new interview on BBC Newsnight, Prince Andrew, 59, has denied that he ever had sex with Jeffrey Epstein’s “sex slave” Virginia Roberts. The Duke of York was grilled by Emily Maitlis during an <a rel="noopener" href="https://www.youtube.com/watch?v=QtBS8COhhhM" target="_blank">hour-long show</a> , where he continued to deny any allegations, despite there being photographic evidence of Roberts and Prince Andrew together. He maintains that he does not recall meeting Roberts and did not spend time with her at a nightclub in London on March 10 in 2001 where she claims they first had sex. Prince Andrew denies sleeping with her as he was at a pizza party with his daughter Beatrice back in 2001. “I was with the children and I’d taken Beatrice to a Pizza Express in Woking for a party at I suppose sort of 4 or 5 in the afternoon,” Prince Andrew said. “And then because the Duchess was away, we have a simple rule in the family that when one is away the other one is there. “I was on terminal leave at the time from the Royal Navy so therefore I was at home.” Interviewer Maitlis asked why he remembers that specific evening so distinctly. “Because going to Pizza Express in Woking is an unusual thing for me to do, a very unusual thing for me to do. “I’ve only been to Woking a couple of times and I remember it weirdly distinctly.” Roberts described their encounter in 2001 in vivid detail, saying that Prince Andrew had been “sweating” as they danced at the nightclub. However, the Duke of York denied these claims too as he said that he doesn’t sweat. “There’s a slight problem with the sweating because I have a peculiar medical condition which is that I don’t sweat or I didn’t sweat at the time. “I didn’t sweat at the time because I had suffered what I would describe as an overdose of adrenalin in the Falkland’s War when I was shot at and it was almost impossible for me to sweat,” he explained. “And it’s only because I have done a number of things in the recent past that I am starting to be able to do that again. So I’m afraid to say that there’s a medical condition that says that I didn’t do it.” However, when the interviewer asked about that specific photo, Prince Andrew said it was “definitely him”. “Oh it’s definitely me, I mean that’s a picture of me. I don’t believe it’s a picture of me in London because when I go out in London, I wear a suit and a tie,” he said. “That’s what I would describe as my travelling clothes if I’m going to go overseas. There’s plenty of photographs of me dressed in that sort of kit but not there.” Friends close to the Duke of York have said they have doubts about the photo’s legitimacy as the hand around Robert’s waist does “not look right”.

News

The excessive sweating condition that could ruin your life

Most people sweat when they exercise or the weather is hot. But some people sweat far more than this. Hyperhidrosis – excessive sweating – can be a devastating condition that has a huge impact on quality of life, and even prevent those who have it from carrying out everyday tasks. For some it has affected their relationships. Others are so embarrassed by their sweating that they feel unable to leave their house. Sweating is a normal physiological process that helps the body to regulate its temperature. When we get too hot or exercise, sweat evaporates from the skin and has a cooling effect. People often also notice they sweat when they are anxious or are in a situation that makes them nervous. But for the roughly 3 per cent of people who have <a href="http://www.bad.org.uk/shared/get-file.ashx?id=93&itemtype=document">hyperhidrosis</a>, sweating can be almost constant. The most common areas of the body affected by hyperhidrosis are hands, feet, underarms, face, and head, although other areas can be affected too. Some people with hyperhidrosis sweat all over, rather than in just some parts of the body. People with hyperhidrosis often sweat in situations where other people don’t, for example, when the weather is cold. It is not known what causes hyperhidrosis, although it is thought that the nerves that usually make us sweat become over-active. Hyperhidrosis often starts in childhood or adolescence, but can start at any time during life. There is probably a genetic element as well, as there is often a family history in people who have excessive sweating of the hands. Few answers Without a clear understanding of what causes hyperhidrosis, it is more challenging to find effective treatments. That is why colleagues and I have been <a href="https://www.dmu.ac.uk/about-dmu/news/2018/january/dmu-begins-research-into-debilitating-condition-that-causes-excessive-sweating.aspx">researching the condition</a>. We asked people with hyperhidrosis and healthcare professionals who treat them what questions they would like research to answer. We had 268 people come forward to suggest nearly 600 research questions. We found that hyperhidrosis has a wide range of severity. At the mild end of the spectrum, the effects may be minimal – a small inconvenience or minor embarrassment. But as severity increases, the impact on quality of life becomes much more substantial. And the condition can have a huge impact on quality of life, affecting people’s career choices and leading to social isolation. For example, some people have such sweaty hands that it makes it difficult to hold a pen or use a keyboard. People with hyperhidrosis often have anxiety in work situations such as job interviews or meetings where they might be expected to shake hands. Their social life can also be affected, with many people feeling embarrassed by their sweating, and some people have avoided forming intimate relationships due to this. Some people have to change their clothes several times. Many people with hyperhidrosis don’t seek medical help due to the stigma of the condition. They may not even know it is a medical condition at all. Those that do often report difficulties in being taken seriously, lack of access to specialists, and treatment being considered a <a href="https://www.cambridgeshireandpeterboroughccg.nhs.uk/EasySiteWeb/GatewayLink.aspx?alId=9620">low priority</a>. Available treatment There are a <a href="https://hyperhidrosisuk.org/treatment-options/">number of treatments</a> available for hyperhidrosis, which depend upon the area of the body affected. Temporary treatments include: <ul> <li>Strong anti-perspirants containing aluminium chloride</li> <li>Iontophoresis, where the affected areas are placed in water and a low voltage electrical current passed through it</li> <li>Botox, which works by blocking a chemical at the nerve endings, so it can’t activate the sweat glands</li> <li>Oral medications, called anti-cholinergics, which also work by blocking the nerve endings, throughout the body</li> </ul> But these are all temporary, and do not work for everyone. The anti-perspirants can cause skin irritation, and oral medication blocks nerve endings throughout the body, so can cause side effects such as a dry mouth and problems urinating. Botox and iontophoresis, meanwhile, need to be repeated regularly and can be expensive. There are also some more permanent solutions available. Some sufferers have had surgery to remove or destroy sweat glands in a localised area (such as the armpits) or endoscopic thoracic sympathectomy (ETS), where the nerves that control sweating are cut. ETS is effective in reducing the sweating of the areas intended, but can lead to very serious side effects such as damage to nerves or organs. Most patients end up with some level of sweating in other areas (<a href="https://www.ncbi.nlm.nih.gov/pubmed/15276490">compensatory sweating</a>) and this can be worse than the original problem, so this surgery is generally only used as a last resort. A newer <a href="https://hyperhidrosisuk.org/treatment-options/miradry/">permanent treatment</a> uses electromagnetic energy to destroy sweat glands. Despite being a common skin condition, hyperhidrosis is not widely known about, and research is very poorly funded. Raising awareness is key if people are to feel comfortable enough to come forward to ask for help and advice.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/113945/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> Written by Louise Dunford, Director of the Institute of Allied Health Sciences Research, De Montfort University. Republished with permission of <a rel="noopener" href="https://theconversation.com/hyperhidrosis-the-excessive-sweating-condition-that-could-ruin-your-life-113945" target="_blank">The Conversation</a>.

Body

Do men really sweat more than women?

Men are generally taller than women, but we do not define gender on the basis of stature. Similarly, our <a href="http://onlinelibrary.wiley.com/doi/10.1113/EP086112/full">research</a> shows we cannot define men and women according to their propensity to sweat (although some parents and partners might suggest otherwise). When we studied men and women during exercise in warm, dry conditions, gender differences in heat loss responses (skin blood flow and sweating) could be explained almost entirely by individual variations in body size and shape. The results refute the common saying “men sweat, while women glow”. How objects - and bodies - lose heat Heat loss from any object is dictated by the ratio of its surface area to its mass, described by the term “specific surface area”. Hot objects with a larger specific surface area cool more quickly than those with a smaller specific surface area. Doubling the radius (size) of a sphere increases its surface area four-fold but its mass eight-fold: this is known as “isometric growth”. Isometrically larger objects don’t lose heat as easily. Shape (morphology) also has a powerful influence on heat loss, so a thin rectangular prism loses heat much faster than a sphere of the same composition and mass. In a <a href="https://theconversation.com/mondays-medical-myth-you-lose-most-heat-through-your-head-10834">previous article</a>, we explained you’re no more likely to lose heat from your head than other parts of your body. Unlike geometric objects, animals do not grow isometrically; we retain a recognisable shape, but our proportions change (this is known as “allometric growth”). This is most evident in children, who have proportionally larger heads and shorter limbs than adults. However, if you double your weight through building muscle and putting on fat (without changing height), this does not result in a doubling of your skin surface area. Such a weight change increases your surface area <a href="https://www.ncbi.nlm.nih.gov/pubmed/2520314">only by about 30%</a>, which translates into reduced specific surface area, and lower heat loss by these physical mechanisms. The larger a person is, the lower is their specific surface area and the less effective these mechanisms become. This is where the physiological mechanisms of heat loss, particularly sweating, come into play in preventing undesirable heat gains. Sweating and evaporative cooling Since humans evolved <a href="http://genome.cshlp.org/content/15/8/1161.full">in the heat of Africa</a>, we acquired an ability to transport heat from deep within our bodies to the skin surface for dissipation via skin blood flow. Similarly, we acquired an evaporative cooling mechanism that can function when the air is hotter than the skin: sweating. These physiological responses enable us to manage body heat, and they are activated when physical heat loss becomes insufficient. To examine the influence of body shape and gender on these two physiological responses to manage body heat, <a href="http://onlinelibrary.wiley.com/doi/10.1113/EP086112/full">we studied</a> men and women (60 university students) of widely variable but overlapping body sizes. Subjects had very similar exercise habits, endurance fitness and amounts of body fat. For each participant, we calculated a target exercise intensity related directly to their skin surface area. This resulted in comparable increases in body temperature across all participants, and equivalent heat-loss requirements. To the best of our knowledge, this was the first investigation to achieve those outcomes across a morphologically diverse sample of men and women. Previous researchers seem not to have fully appreciated these important experimental design criteria, leading to experiments that perpetuated the myth that all men sweat more than women. Our analyses have shown that variations in skin blood flow and sweating between men and women are dependent not on gender, but on body morphology. In answering our questions, we demonstrated that the lyrics of <a href="https://en.wikipedia.org/wiki/Down_Under_(song)">“Down under” (Men at Work)</a> require modification. <blockquote> Do you come from a land down under? Where women glow and men plunder? </blockquote> While we do come from a land down under, and while some men may unfortunately still plunder, women do not glow. They sweat just like men, and for the same reason: to lower body temperature. Three different types of sweat To consider the question of how sweat relates to body odour, we need to go a bit broader. The ubiquitous sweat glands humans possess for evaporative cooling are known as “eccrine” glands. However, we all have two other types of glands in our skin: <a href="https://www.ncbi.nlm.nih.gov/pubmed/3812728">“apocrine” and “apoeccrine” glands</a>. While eccrine glands are found distributed throughout the body, apocrine and apoeccrine glands have a limited distribution, predominantly located in regions where adults grow longer - sometimes curlier - hair (regardless of whether we remove that hair). The apocrine glands are found beside hair follicles, where they secrete a milky, oily fluid. The apoeccrine glands, which appear to develop after puberty, seem to be the dominant gland within the armpits. They secrete a watery fluid like the eccrine glands. The odour we sometimes detect around sweaty people, or their clothes, comes mostly from secretions of the apocrine and apoeccrine glands. Those secretions are initially odourless, but bacterial action on that fluid leads to smelly men, and smelly women.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/73903/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> Written by Sean Notley, Postdoctoral Fellow, University of Ottawa and Nigel Taylor, Associate Professor of Thermal Physiology, University of Wollongong. Republished with permission of <a rel="noopener" href="https://theconversation.com/health-check-do-men-really-sweat-more-than-women-73903" target="_blank">The Conversation</a>.

Body

What causes body odour

Body odour. No matter what the time of the year, it just plagues some people. When you smell somebody's B.O., it's easy to assume they have just been exercising, have poor hygiene or simply don't use deodorant. Lots of other factors can influence the way you smell, however. Body odour, also known as bromhidrosis, osmidrosis or ozochrotia, is a smell we think of as offensive and occurs when the bacteria that lives on the skin breaks down sweat into acids. Sweat itself is odourless; it's simply the bacteria breaking down the protein in it that causes the bad smell. Two different acids usually cause this smell: propionic acid and isovaleric acid. Propionic acid is what breaks down from propionibacteria, which lives in the sebaceous gland ducts. It has a particularly vinegary smell. Sovaleric acid, on the other hand, results from the bacteria Staphylococcus epidermidis, and has a pungent, cheesy smell. We humans have two types of glands, eccrine and apocrine. Eccrine glands are those responsible for regulating our body temperatures; they're all over your skin. The sweat produced from these glands is salty and harder for bacteria to break down the protein in them. Apocrine glands around found in your armpits, genitals, breasts, eyelids, and ears. The sweat from these glands is much more easily broken down into protein by bacteria, which quickly multiplies and causes the majority of body odour. There are several factors that can influence how much you smell (and how offensive that smell is) when those apocrine glands are working their way into bacterial overload. Genetics, like with many bodily functions, are a core influencer of one's B.O. The gene ABCC11 is responsible for axillary body odour and the more functional this gene is, the more encouraging it will be for bacterial growth from your apocrine glands. This is also determined by your heritage: around 80-95 per cent of people with East Asian backgrounds (Chinese, Japanese, Korean) have a non-functioning ABCC11 allele, meaning lower likelihood of producing body odour. Most other ethnic groups only have 0-3 per cent have this non-functioning allele, so the large majority of those groups are prone to axillary odour. A genetic condition called trimethylaminuria, which is colloquially known as "fish odour syndrome", may also be the culprit. Although rare, this metabolic disorder hinders your body's ability to break down trimethtylamine (found in choline-rich foods like eggs, certain fish, and some legumes). When trimethtylamine builds up in the body, it creates a fishy stink. A dietary imbalance of magnesium or zinc can contribute to offensive body odour as well. One of the main things zinc does is processes carbohydrates into waste, but if you don't have enough of it, this clearing process is hindered and odours can ensue. Low magnesium, additionally, causes slower emptying of the bowel and this can also have an effect on your body odour. Then there's certain foods that can contribute to negative odour. Red meat, garlic, onions, broccoli, Brussels sprouts, and strong spices such as curry powder can also encourage negative odours, as can alcohol, tobacco, and caffeine. What can you do about offensive body odour? Frequent showering is the obvious one, but for those that struggle this simply isn't enough. One solution can be to reapply deodorant multiple times a day. Clinical strength antiperspirant deodorants may prove helpful but prescription versions from a GP may also be more helpful than over-the-counter products. Body odour also clings to material, so fresh clothing and natural fabrics that breathe (e.g. cotton rather than synthetic blends) can mitigate odours and give them less time to permeate. Sweat will also evaporate quicker through natural fabrics. Shaving your armpits, too, gives the odour less to stick to, and don't rule out a midday change to a fresh shirt. There's nothing you can do about your genes, but you can reduce or cut out the aforementioned foods and gauge the change in the way you smell. You may find one of them, all of them, or a combination affect you. Written by Lee Suckling. First appeared on <a href="http://www.stuff.co.nz/" target="_blank">Stuff.co.nz</a>.

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