Body odor, also known as underarm odor and smelly sweat, is the sweat discharged from the apocrine glands (also known as apocrine glands) in the armpits, vulva and corners of the mouth of patients, and its fatty acid is higher than that of ordinary people, showing light yellow and thicker; When the fatty acid reaches a certain concentration, it is decomposed by bacteria on the skin surface, mainly staphylococcus, producing unsaturated fatty acids and giving off a bad smell. It is similar to the smell discharged from fox's anus, so it is often called body odor.

Because yellow people's body odor is extremely light, once someone's body odor is heavy (body odor is obvious), people around them feel particularly pungent and generally think it is a disease. Suffering from body odor will cause a heavy psychological burden and affect marriage, employment, further studies and making friends. As a result, many patients have abnormal personality and thinking, and body odor has really become a psychological disease.

Often occurs in the palm and sole, rubbing area, and sweating is often colorless and tasteless. However, in the case of hyperhidrosis, sweat is interpreted by parasitic bacteria on the skin surface to release fatty acids and produce a special smell; Other substances such as garlic and arsenic can be excreted through exocrine glands, thus producing odor.