Science

Why do we sweat?

It’s a simple fact: everyone sweats. For some, it’s more like a glow; for others, it’s like a leaky faucet. But no matter how you sweat or how much you do it, it’s part of life for every single human being.

Curious about why we sweat? Here, we’ll talk about a little bit of the science behind sweat, including why we do it and some fascinating facts you may not know.

Why do we sweat?

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To help you understand how sweat works, let’s start with a visualization exercise. Start by thinking about a house. Say that you want to keep that house at 70 degrees at all times. To do that, in the winter you’d probably need to turn on the heat, and in the summer you’d likely need to turn on the air conditioning to keep the temperature steady.

Now, think about your body like that house. Inside of your body, your inner thermostat is pretty much always set to 98.6 degrees F (or 37 degrees C), which is the temperature at which the body works best.

But unlike that house, when you get hotter than 98.6 degrees, you don’t have central air to turn on. Instead, a signal is sent to your hypothalamus, which regulates all sorts of bodily and hormone functions. Your hypothalamus then reacts by telling your body it’s time to sweat.

How does sweat happen?

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Once your hypothalamus tells the body to start sweating, the eccrine glands (your primary sweat glands) start to make sweat, which is composed of water with a few other assorted ingredients, including minerals, urea, and salt.

Sweat exits the body through your pores. Once that sweat is out of your body and makes contact with the air, it begins to evaporate — and as this happens, it has a cooling effect on the body.

It’s worth noting that while this is generally an effective method of cooling the body, if you’re sweating a lot, such as during a really hot day or a really intense workout, you may be releasing quite a bit of water. Be sure to drink lots of water to replenish the liquids.

Facts about sweat

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Want to expand your knowledge about sweat? Here are some interesting facts you may not know:

We need to sweat. As embarrassing or annoying as sweat can be sometimes, it is in fact a necessary bodily function. Without it, our bodies would not be able to regulate temperature.

Not all sweat smells bad. True: sometimes sweat stinks. But actually, it’s not the sweat that is to blame. What we blame on sweat is actually the interaction when sweat hits your skin. It reacts with bacteria on the skin, which can give sweat a bad smell. Frequent washing with soap and water can help, as can deodorant or an antiperspirant.

We don’t just sweat when we’re hot. Have you ever broken into a sweat when speaking in front of a crowd, before a big test, or during a stressful situation? If so, you can probably attest to the fact that sweat isn’t just a result of being hot.

As it turns out, the hypothalamus, which is responsible for making you sweat, is also responsible for a variety of other activities, including metabolic processes and the release of hormones.

When you sweat due to heat, the hypothalamus sends a signal to the eccrine glands to sweat. However, when you’re under stress, it sends a signal to the other sweat glands: apocrine glands. These larger glands, which are located in the parts of your body with more hair (such as the armpits and genitals), secrete “stress” sweat. This sweat is different from sweat solely based on heat and contains more protein and fat. When these proteins and fat combine with the bacteria on your skin, they can result in body odor, which is also why stress sweat smells worse.

Feeling that glow?

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While sweating isn’t always comfortable, it is a completely natural bodily function. It’s almost like having a built-in sprinkler system that helps your body maintain its optimal working temperature of 98.6 degrees. So next time you start feeling that glow, remember: It’s just your body’s way of keeping all systems in check.