98 ~ 99% of the composition is mainly water, with a specific gravity of about 1.002 ~ 1.003 and a pH value of 4.2 ~ 7.5. NaCl is about 300mg/ 100ml.
1 ~ 2% is a small amount of urea, lactic acid and fatty acid.
Sweat is the liquid secreted by sweat glands. Sweating due to thermal stimulation caused by the increase of external temperature or internal heat production is called perceptual sweating. At this time, the sweating area is widely distributed, and the skin in all parts of the body, especially the forehead, neck, trunk, waist, back of hand and forearm, is the most; Followed by the neck, trunk side and most limbs; Once again, the inner thigh and armpit; At least the palms and feet. Mental stress can also lead to sweating, and sweating centers are distributed in all parts of the central nervous system. Normal people unconsciously evaporate about 600 ~ 700 ml of water within 24 hours.
Sweat, my friend!
Sweating is divided into active and passive. Passive sweating refers to sweating due to sultry weather and irritability, which is harmful to human body. On the contrary, the sweat that the human body actively exercises is called active sweating, which is conducive to maintaining the temperature in the human body and emitting heat, which is beneficial to people's physical and mental health.
The function of sweat is to regulate body temperature. Think about it carefully, the human body is really like a precise machine. If you don't sweat, that's not good. As soon as you exercise, your blood circulation will speed up and your body temperature will rise. Naturally, you will sweat and your body temperature will drop. When it is cold, sweat glands and pores contract, thus stopping sweating and preventing body temperature loss.
Sweat is the "air conditioner" of our body. Chinese medicine believes that sweating is a kind of detoxification in summer. There are two ways for people to detoxify: one is urination, and the other is sweating. Sweating is the most effective way to detoxify. Only in summer can you sweat naturally all year round, which will be good for human metabolism, meridian balance and immune system health. If you don't sweat for a long time, your skin won't breathe, which will eventually cause many disorders in your metabolic system, and the detoxification function of this skin will be transferred to your kidneys and liver.
Sweat, enemy!
Sweat components can be divided into inorganic components and organic components, both of which are metabolites in the body. Inorganic components are mainly salts such as sodium chloride and calcium carbonate, some of which are acidic and some are alkaline. Excessive accumulation of these acid and alkali components will directly corrode the skin, destroy the tissues and cells of the skin, and lead to skin aging. The accumulation of organic components in sweat on the body surface is more conducive to the reproduction of microorganisms on the body surface under the impetus of high temperature weather.
Due to air pollution and the use of equipment in gymnasiums, a large number of bacteria and parasites on the skin surface will decompose the organic components in sweat, produce various toxic substances and release malodorous gases, thus producing a serious "sweat odor" and even causing skin diseases, which are also commonly known as sweat rash, folliculitis, eczema, boils and miliaria.
In addition, sweating will reduce the resistance of the skin. Sweat and sebum are secreted normally, and form a sebum film after mixing on the skin. Excessive sweating, the proportion of sweat and sebum is unbalanced, and sebum will be washed away by sweat and become thinner. Generally speaking, normal weak acidic skin will become alkaline, so the resistance of bacteria will be weakened and the bactericidal power will also decrease. Some people will have skin diseases, and some people's skin will become rough.