Armpit odor, commonly known as “fox odor”, is also known as ophidrosis, a common condition among young people. Especially when summer comes, the patient’s body odor is abnormal, seriously affecting the patient’s daily interactions, and even work. Therefore, patients often show an introverted, withdrawn personality, low self-esteem is more obvious. The exact cause of axillary odor is not very clear, but it is generally believed to be related to the abnormal secretion function of the sweat glands. The sweat glands are only found in the armpits, areola, anus, vulva and external ear canal. The mechanism of axillary odor is due to the fact that the sweat glands in the armpit are too abundant and secrete too much sweat, which is decomposed by bacteria (Staphylococcus epidermidis, Gram-negative bacilli, etc.) in the moist parts of the armpit and emits a typical pungent odor. The pungent odor of axillary odor is caused by unsaturated branched-chain fatty acids of six to ten carbons, mainly 3-trans-2-methylhexanoic acid and 5-androstenone. The secretion of the sweat glands is influenced by the gonads. Before puberty, because the sweat gland is not mature, no secretion function, no fox odor. By puberty, the secretion of the gonads is high, and the secretion of the sweat glands is also higher, and their odor also appears obviously foul. In fact, many patients sweat itself does not smell, but contains substances that can be easily decomposed by bacteria, because the axillary skin is warm and humid, poor ventilation, there are often a large number of bacteria breeding, when the sweat of the sweat gland excretion to the surface of the skin, the decomposition of these bacteria, thus emitting an unpleasant odor. Therefore, this disease is most often seen in young adults, to young women are common. With age, the human body declines, the sweat glands also gradually degenerate, the symptoms can be reduced or disappear, most patients have a family history of heredity. Axillary odor has a certain degree of heredity and ethnicity. Part of the family history, may be related to genetics, about 80% of the father or mother to their children, the mode of inheritance is dominant. The incidence of Han Chinese in China is 6%, in the West about more than half; and in China, more people in the South and less people in the North, the incidence of Western whites and blacks is higher. In addition, climate change, growth and development of hormone secretion disorders, fatigue, etc. are also triggers for the onset of axillary odor. A small number of oedema arises when the mental and nervous system is damaged, such as paranoia and schizophrenia.