5 facts about sweat

Sometimes, we wish we didn’t have to sweat. But despite the inconvenience (stains, odour, discomfort), it’s totally necessary! But why? And what’s the best way to deal with it? We’ve got the answers!


Sweating is triggered by the hypothalamus (part of our nervous system) when your body temperature exceeds its normal threshold of 37° C, like during heat waves, intense sports or when you have a fever, etc. Your body expells water to reduce your temperature, as if releasing steam. Sweating can literally save you: if your body temperature is too high, you run the risk of thermal shock.


Sweat is also good for your skin. It helps your hands and feet get better grip, and, combined with sebum, a hydrolipidic film, it helps keeps your skin hydrated and resistant to external aggressors like pollution, dust, wind, sun and microbes, etc.


Sweat is water, for the most part. It also contains a small amount of minerals, lactic acid and urea –all odourless ingredients.  So, why do we smell when we sweat? The culprits are cutaneous bacteria that feed on our sweat. The more these microorganisms have time to feed, the more the odour intensifies. That’s why it’s important to wash as soon as possible after sweating a lot.

Sweat glands

There are two types of the approximately 3 million (!) glands that produce sweat.

The eccrine glands are found all over the surface of the body and are most abundant on the palms of our hands and the soles of our feet. The sweat that these glands produce is mainly composed of water and mineral salts. It contains very little food for bacteria and is therefore odourless.

The apocrine glands, the second type, are found in our armpits and genital area. They appear once we hit puberty and secrete a sweat that’s rich in fat, the favorite food of bacteria, which is why these areas produce odour when we sweat.


Normally, an individual will produce 500 ml to 1 litre of sweat per day. However, a person can produce up to four litres of sweat per day in hot weather. And during physical activity, the human body can produce up to 10 litres! Armpit sweat is only a small quantity of what the entire body produces. During a normal day, armpits produce about a tablespoon of sweat. This is why an antiperspirant doesn’t prevent sweat from regulating your body temperature.


In general, women sweat less than men do. But everyone has their own "profile" and some people produce a lot more sweat than others under the same conditions. There are several hypotheses as to why: hormonal changes or hyperactivity of the nervous system or sweat glands, etc.

Stress also makes you sweat!  Who hasn’t wiped off a few beads of sweat before a major presentation or job interview? Provoked by an emotional stimulus, stress-related sweat is produced quickly, regardless of the ambient temperature. Its composition also differs from normal sweat: it contains hormones and nutrients that make it particularly attractive to bacteria. This is why stress-related sweat has such a stronger odour.


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5 facts about sweat

Why do we sweat? Where does body odour come from? What quantity of sweat should we secrete?