Bodily fluids don’t tend to get much praise.
And yet none of us would last long without the ability to perspire.
Perspiration is normal, and even healthy, but we all sweat to different degrees at different times.
Some of us are soaked in sweat after a quick sprint to catch the bus.
Others can run for miles and you won’t spot a droplet on their foreheads.
From the impact of hair on body odour to how sweat changes your suntan, here are seven essential facts about perspiration:
Many people are embarrassed when sweating heavily, may it be due to exercising, stress or high temperatures.
It may help you in the future to remind yourself that your body is just doing its job.
“Perspiration helps to regulate the body’s temperature so that the ideal temperature of about 37°C is not exceeded,” says Dr Peter Elsner, who heads a dermatological clinic affiliated with the university hospital in Jena, Germany.
“The sweat on the skin serves to cool down the body through so- called evaporative cooling,” he explains.
The brain activates the millions of sweat glands located underneath the surface of the skin via sensors.
These secrete sweat, which then evaporates and cools the skin.
This works better in dry heat than in high humidity, which is why a gust of wind or a fan has a doubly refreshing effect.
Humans have to constantly maintain their body temperature for all functions to work properly.
If your body temperature is too high due to heat or exertion, there is a risk of overheating, which can cause headache, dizziness and nausea.
Even without exercise or heat, the body still secretes about half a litre of sweat every day – usually without you noticing – according to the German Dermatological Society (DDG).
And some people tend to sweat more than others.
This can be unpleasant, especially if it affects your palms or armpits.
There are different potential reasons for excessive perspiration, such as:
- Conditions such as hyperhidrosis, i.e. excessive sweating
- Genetic factors
- Highly sensitive sweat glands.
When it comes to excess sweat, there are different treatment options, according to Dr Elsner.
- Dermatological treatments with locally-active preparations, e.g. antiperspirants, gels, lotions, ointments and tablets.
- Electrical procedures to regulate sweat production.
Iontophoresis, for example, sends a weak electric current through the skin, leading to a temporary decrease in sweat gland activity.
- Surgical measures in which doctors remove your sweat glands or use thermal energy targeting and eliminating them.
- Botulinum toxin injections into the armpits to block the sweat glands there.
Excessive sweating, or the lack of perspiration altogether, can also be due to hormonal changes, e.g. during menopause.
Other possible causes are metabolic diseases, tumours or neurological conditions.
“Some rare, serious skin diseases cause the sweat glands to stop functioning,” says Dr Elsner.
“If you are suffering from such a condition, you should try to avoid excessive heat.”
He also recommends differentiated dermatological diagnostics and counselling.
The vital principle of evaporative cooling – which allows the body to shed excessive heat – doesn’t work if you’re wearing skinny jeans and a long-sleeved shirt.
In order for the sweat to evaporate, it needs to be in contact with air.
Wearing light, loose clothing allows your skin to breathe.
If you want to avoid underarm sweat stains, stylist Andreas Rose recommends you try out sweat pads, which are applied to the inside of your clothing and directly absorb the moisture there.
Sweat has a harder time evaporating in some areas of your body than others, like your armpits or genital area, potentially leading to a higher risk of bacterial or yeast infections, says Dr Elsner.
The best remedy?
Wash those areas daily.
Whether after a heavy workout or during a heatwave, staying hydrated is vital to compensate for the loss of fluids through sweating.
Otherwise, you risk circulatory collapse, according to Dr Elsner.
Sweat consists of 99% water, but the remainder contains salts, i.e. electrolytes.
“It’s important to not only drink tap water or tea, but to also take electrolytes.
“Otherwise, hyponatraemia, i.e. low sodium concentration in the blood, can occur,” says Dr Clemens Becker from the Robert Bosch Hospital in Stuttgart, Germany.
Try drinking mineral water with a high sodium content to prevent dehydration.
A high level of sodium is about 200 milligrammes per litre.
According to the German Nutrition Society (DGE), adults should drink some 1.5 litres per day, and even more on hot days.
Perspiration doesn’t always smell.
It depends on how old it is and what kind of sweat glands have produced it.
There are two different kinds of glands that secrete sweat.
Eccrine sweat glands are distributed across the entire body.
They mainly produce sweat that doesn’t really smell, as it mainly consists of water.
You will only start noticing this kind of sweat when it’s older and bacteria have started to decompose it.
“When under stress, the body also releases other substances besides sweat, which can change the smell,” explains Dr Elsner.
Meanwhile, apocrine sweat glands are mainly located in the armpits, the areola and nipples of the breast, and the genital area.
They are not involved in cooling the body, but are responsible for your individual odour.
Perspiration in these areas can smell strongly real quick, because apocrine sweat glands secrete a more oily fluid that is a hotbed for bacteria.
Once bacterial degradation has started, your sweat will start to emit a pungent smell.
Body hair also promotes odour formation because it traps sweat and bacteria on your skin.
A quick trim can work wonders.
You can also apply deodorant or antiperspirant to minimise the smell from perspiration.
Deodorant counters odour by masking it with fragrance.
Antiperspirants contain aluminium-based ingredients that block your body’s eccrine glands and temporarily reduce perspiration.
Some natural solutions to prevent your sweat from becoming smelly include:
- Wearing loose clothing, best made out of natural fibres like linen or cotton.
- Consuming sage – a natural remedy to inhibit perspiration.
Three cups of sage tea per day are recommended.
- Applying a paste of baking soda and baking powder mixed with some water, to your armpits.
Wash it off after 15 minutes.
- Cider vinegar, which causes your sweat glands to contract.
Rub it into the armpits before going to bed, leave it on overnight and shower off in the morning.
Some people are convinced that sweating in the sun means that you’ll tan more quickly.
“To my knowledge, there’s no scientific evidence supporting the claim that perspiration accelerates the tanning process,” says Dr Elsner.
However, sweating can reduce the effectiveness of sunscreen, and therefore increase the risk of sunburn, he warns.
This is as sweat can dilute the sunscreen on the skin, and thus weaken its effect.
Meanwhile, due to the evaporative cooling effect of sweating, you might be able to hold out in the sun longer than is good for the skin and become more tan.
But that also increases the risk of sunburn, he says.
Sweating isn’t only a vital body function due to its cooling effect on the skin.
Dr Elsner also names a number of other positives related to sweating:
- Giving a rosy complexion
Perspiration promotes circulation and moisturises the skin, making it look firmer and more radiant.
- Performs a cleansing function
Sweating also removes waste substances and dead skin cells.
- Acts as a protective coat
Your skin is constantly busy fending off germs.
Sweat is an important ally in this process, as its acidic pH value kills many bacteria and viruses.
- Has an antimicrobial function
Dermcidin is a substance produced by the sweat glands that has an antimicrobial effect, which helps contribute to healthy skin flora. – dpa