Sweat is a clear, salty liquid produced by glands in the skin. Sweating is how the body cools itself. You sweat mainly under your arms and on your feet and palms.
Sweating a lot is normal when it is hot, during exercise, are anxious, or have a fever. It also happens to women going through menopause. If you often sweat too much, it's called hyperhidrosis. Causes include thyroid or nervous system disorders, low blood sugar, or another health problem. Sweating too little, anhidrosis and it can be life-threatening because the body can overheat. Causes of anhidrosis include dehydration, burns, and some skin and nerve disorders.
Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distributed over much of the body.
Maximum sweat rates of an adult can be up to two to four quarts per hour or 10 to 15 quarts per day, but is less in children prior to puberty. Evaporation of sweat from the skin surface has a cooling effect so in hot weather, or when the individual's muscles heat up due to exertion, more sweat is produced.
Animals with few sweat glands, such as dogs, accomplish similar temperature regulation results by panting, which evaporates water from the moist lining of the oral cavity and pharynx.
Primates and horses have armpits that sweat like those of humans. Although sweating is found in a wide variety of mammals, relatively few (exceptions include humans and horses) produce large amounts of sweat in order to cool down.
Humans between 2 and 5 million sweat glands spread across the body.
The fitter you are, the sooner you may start to sweat during exercise. This is because your body recognizes the need to cool you off faster. The Gatorade Sports Science Institute has found that in conditions of 85 degrees and 40 percent humidity, the average runner will lose 2 to 4 pounds of sweat an hour. During intense exercise in the heat, athletes can sweat off 2 to 6 percent of their body weight.
Women have more sweat glands than men, but men’s sweat glands actually produce more sweat than women’s.
Men have slightly saltier sweat than women, and they also sweat, on average, 40 percent more than women.
Overactive sweat glands (also known as hyperhidrosis) can be caused by certain medications or medical conditions. Hyperhidrosis can be embarrassing to deal with and can even lead to dehydration. About 3 percent of the population suffers from or excessive sweating.
Some people have salty sweat. If your sweat stings your eyes or stings if it trickles into a cut, tastes salty or leaves white streaks on your skin or clothes after exercising, you're a salty sweater. It could be caused by a salt imbalance and a doctor should be consulted.
There is a difference between stress sweat and regular sweat. Regular sweat is comprised of water, salt and potassium, and helps cool the body down as it evaporates. Stress sweat is released by a different gland and is comprised of fatty acids and proteins. Stress sweat doesn’t evaporate as quickly as regular sweat and can develop an odor when it combines with bacteria on the skin. Sweat itself is odorless. It’s the bacteria on the skin that mingles with it and produces body odor.
Vegetarians’ sweat smells better. A study in the Czech Republic asked women to rate the body odor “attractiveness” of both red meat eaters and people who abstained from red meat. In the end, the non-meat eaters’ odors were rated significantly more attractive, more pleasant and less intense.
Sweat glands are most concentrated on the bottom of our feet and least concentrated on our backs.
Yellow underarm stains are caused by your apocrine glands, which contain proteins and fatty acids and thus make underarm secretions thick and milky.
Hippo sweat is red. Cows sweat through their noses.
Eating can make you sweat; when you eat your metabolism increases, which boosts your body temperature. You then sweat in order to cool down. Primates and horses have armpits that sweat like human armpits.
A group of Swedish engineers has built a “Sweat Machine” that pulls the sweat out of damp clothing, and then purifies and filters it until it’s fit to drink. I am not sure why they wanted to do this.