We tend to sweat at the most inopportune times (right before a first date or an important presentation), but sweating is actually an essential part of your physiology. Read on to find out why it's good for, and how to tell if you sweat too much.
What is sweat?
Sweat is mostly water and salt, with small amounts of other substances, including minerals and electrolytes.If you believe a good sweat can also rid your body of toxins (possibly stockpiled because of a stressful fight with your mother or a too-late night out with the girls), it's unfortunate to have to report that that’s not the case. Detoxing is the liver’s job.
You have between 2 million and 4 million sweat glands spread over your entire body (except for a few choice areas, like your lips and nipples). While armpits have one of the highest concentrations, the glands are actually everywhere. “We have them on our palms, on our soles — we have them throughout the body,” says Cameron Rokhsar, MD, an associate professor of dermatology at Albert Einstein College of Medicine in New York City.
Two types of sweat glands are involved in perspiring. Eccrine glands, which respond to heat, are located just about everywhere on your body; they release an essentially odorless sweat directly onto your skin to cool your body. Apocrine glands develop in your hair follicles — on your scalp and in your armpits, for example — and they respond to heightened emotions as well as to heat. They release a fatty sweat that's broken down by bacteria on the skin, in a process that produces a stink.
Why do we sweat?
Sweat glands are activated when you're hot or when you're experiencing stress. “The sweat glands are under the control of the nervous system,” says Dr. Rokhsar, who is also the medical director of the New York Cosmetic, Skin and Laser Surgery Center. “So you can sweat when you’re in a flight-or-fight situation and become upset or angry, just as you do when you become hot, such as when you’re exercising.”
No matter how hard you try, though, there’s no real way to control the amount you sweat. “Just like much else, it's genetically determined,” says Rokhsar. So if you sweat buckets after a 3-mile run and your running buddy looks as though she just took a leisurely stroll, blame your genes.
How do you know if you sweat too much?
The average person sweats about four cups a day. But if you feel as if you sweat more than others do, you probably do. “It’s somewhat subjective,” says Rokhsar. “If you feel that you sweat too much, you sweat too much.” To avoid letting your overactive glands put a damper on your social life, try an aluminum-based deodorant or discuss other options with your dermatologist.