Body odor is also called underarm odor, smelly sweat and so on. It is because the fatty acids in the sweat discharged by the apocrine glands (also known as apocrine glands) in the armpits, vulva, breasts and corners of the mouth of patients are higher than those of ordinary people, showing light yellow and sticky shape. When the fatty acid reaches a certain concentration, it is decomposed by bacteria on the skin surface, mainly staphylococcus, to produce unsaturated fatty acid, which gives off a fox-like smell-that is, we often say fox odor. Generally, body odor runs in the family and is a hereditary "disease". The acquired incidence rate only accounts for about 3% of the patients. Body odor is closely related to race. White people, black people and brown people have the largest proportion of body odor. Therefore, there is no body odor, which is rare or abnormal. Body odor is not a disease in their population. In the west, the English meaning of the word body odor means body odor, not body odor. The cause of body odor is that fatty acids in sweat excreted by human body cannot be completely or basically decomposed by lipase, resulting in excessive fatty acids in sweat excreted, and fatty acids are decomposed by bacteria (mainly staphylococcus) on the skin surface to form unsaturated fatty acids, resulting in odor, namely body odor. Sweat gland is the simplest single-tube gland in the skin. In the dermis, the tubules are coiled into a ball, which is the sweat gland, which is the headquarters of sweat secretion. The way of sweat gland secretion is that water and fat are secreted to the sweat gland wall through osmotic pressure difference, and its formation process and composition are similar to those of urine, both of which are excretion processes of body fluids. Therefore, body odor is only hereditary and not contagious.
Sweat causing body odor is discharged through the sweat tube (single tube), and the sweat penetrates into the sweat tube through the sweat tube wall. The sweat tube wall acts as a barrier for filtering sweat and prevents other cells and substances from entering the sweat. Therefore, the size of cell gap in the sweat tube wall is a necessary condition for discharging the composition of sweat. The cell gap in the sweat tube wall is usually within 70 microns, and only water and some ions (such as salt ions) can be filtered freely. If the intercellular space of sweat tube wall is more than 80 microns, fat molecules (i.e. macromolecules) can penetrate into sweat tube wall and be excreted with sweat. These fatty acids are fatty acids, which are decomposed into unsaturated fatty acids by bacteria in vitro, which will produce body odor. This is the process of body odor formation.
The cause of body odor is self-evident, that is, the intercellular space of sweat gland wall is more than 80 microns, which is influenced by human species and heredity. The offspring of couples who both have body odor have 80% genetic probability, one of them has 50% genetic probability, and there is a small probability of atavism. Body odor itself is not a disease and does not affect the normal physiological function of the human body. At the same time, it also has the function of "pheromone" to transmit sexual information between the two sexes. Generally, people with body odor are healthier than those without body odor, so it is also a sign of health.