Why do We Sweat?

Garry Crystal

Sweating is the body’s natural way of cooling us down. Although it may feel as if the sweat or perspiration is making us hotter, especially on warm days, without sweat, we would not be able to tolerate the heat our bodies would produce.

A diagram of the human skin, including sweat glands.
A diagram of the human skin, including sweat glands.

We sweat in order to keep the body at its normal temperature, which is 98.6° Fahrenheit (37° Celsius). If we lost this bodily function we could suffer from heatstroke in hot weather.

Drinking water is important to prevent dehydration from sweating.
Drinking water is important to prevent dehydration from sweating.

Think of all the food the body takes in each day. This has to be burned off somehow. The burning of this food produces heat within the body which triggers our brain to kick start the body’s natural cooling process. Inside the human body are long, twisting tubes of cells known as the sweat glands. The blood vessels in our skin open and the fluid is released through our pores.

Sweating is a natural function of the body.
Sweating is a natural function of the body.

There are approximately 2 million sweat glands in our body. We may not realize it but we perspire even when it is a cold day and we are not doing anything particularly strenuous. The body is two-thirds water and we lose a great amount of this every day through sweating. This is why it is so important to drink approximately 2 liters of water each day in order to replenish the lost fluids.

Sweating allows the human body to maintain its normal temperature.
Sweating allows the human body to maintain its normal temperature.

There are two different types of sweat glands: the Eccrine and the Aprocrine glands. The Eccrine is the more common of the two and is found in parts of the body such as the forehead, palms of the hands and soles of the feet. The Aprocrine can be found in the armpits and the end of the hair follicles.

Sweating works to cool the body off.
Sweating works to cool the body off.

Sweat itself is made up of different elements. The most common elements are water and sodium, otherwise known as salt. At times, we can have a low sweat production--this happens when it is cool and we are resting. The higher sweat production occurs in very hot weather or when we are exercising. High production contains about 20 percent more sodium than low sweat production.

Higher sweat production occurs to cool the body down when people exercise.
Higher sweat production occurs to cool the body down when people exercise.

There is also a difference in the chemical elements when we perspire. Perspiration that is produced through the Aprocrine glands, or in the armpit, will be thicker and perhaps have a yellowish color. This is because it contains fatty acids and proteins. It is this type of sweat under the arms, coupled with antiperspirants, which can turn clothing yellow. Notice when we apply deodorants it is only to the armpits, in order to counteract the smell of the Aprocrine sweat. Sweat is actually odorless, but when it starts to decompose and is attacked by bacteria, the smell can be unpleasant.

Endurance athletes can lose much water and electrolytes through sweat.
Endurance athletes can lose much water and electrolytes through sweat.

In countries with hot climates such as India, the people have a very much higher salt intake than would be considered healthy for us. It can be assumed that this is because they lose a large amount of chemicals such as salt through perspiration. Sweating, although at times embarrassing, is a natural bodily function crucial to our survival.

Sweat glands are located all over the body.
Sweat glands are located all over the body.

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Discussion Comments


I also have lost weight (not by choice) in the last few years, and notice I don't sweat from exercise or sitting in a sauna. I've mentioned to a few doctors (neurologist and dermatologist) and they don't seem to be concerned or have an explanation. It would be good to know. I'm 53 years old. --LB


I used to have a problem with sweating and would always sweat even when cold. However, after a few appointments at the doctor, I spoke to the man who does my botox and he told me of a procedure where they inject botox in the underarm. It basically inhibits the sweat glands under the arm from producing any sweat at all.

It is really effective although the downfall is the price of botox these days. I found this very helpful because I am 19 years old and getting my education and sweating while I was socializing was a massive problem for me.

The only downside is I sweat on my forehead and feet a tiny bit more. I can only presume that this is to counteract the now useless underarm sweat glands. Hope this helped.


fat cells hold more water, so fat people sweat more than skinny people.


Hi David: I am no expert in this but from what I can tell, it is probably your body's readjusting itself to your now reduced weight. Previously when you were 80 lbs heavier, everything that you do, that your body does are a challenge because of the excess weight, fat. Also, heat retention is higher in a fat body as compared to a slim body.

Now, with less weight you and your body are operating at a more optimum level, without the need to exert as much as before. This could be the reason you're sweating less. --Steven P


If it is necessary to wear warm clothes after sweating? My sports teacher always recommended wearing a jacket after a work-out when we sweat. Why?


i am 10 and i already sweat, why?


I work at a health club and I have an ongoing debate with a few people that the people that have the most sweat work out harder. is this true? One of my friends says she just does not sweat but she works out hard.


Thank you! this article helped us on my science fair project we're working on. We want to create a new type of drink that works as well as Gatorade. LOL. Anyway, thanks! Jamie, Tony, Alicia, Martha, and Egor


Why does cold sweat smell different than hot sweat?


Why do i sweat all the time?


Ah, thanks for the explanation. I just happened to wonder *why* we sweat and why it smells. Thanks. :p


that's how bodies work. i'm a scientist. if it weren't for sweat your body will go wrong,trust me. what will you do without science?


i am really fed up with the excessive sweating. is there any natural method to prevent the unpleasant smell.


Is it true that we sweat so that the water cools us off? Or do we sweat to relieve the heat from our body? I'm in an argument and need to know ASAP so that I can either prove that I am right or drop it so I don't feel like an idiot.


Lol helped my science project thanks.


Why would someone sweat in winter in countries like Canada? At home with regular heating, or outdoor when the temperature is below 30c? Is there any thing wrong with the person? Is that a disease? Anxious, please help.


Wow! This really helped with my HW! Thanks soooo much!


I need to know how I can prevent the yellowish color? please its putting me in awkward position because I don't want my lover to wash my clothes..



Hi, Is it true that sweating because when water vapors, it takes in a lot of kinetic energy which is an endothermic reaction, and therefore it makes the condition much more cooler? thanks a lot.


i have lost 80 lbs. in the past year. by exercising and changing eating habits, however, i do not sweat even in a sauna at 180 degrees. i used to sweat profusely. can anyone tell me an answer?


david b.

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