Armpit odor is a special odor produced by the secretion of sweat by the parietal sweat glands in the armpit area, which is decomposed by bacteria. Armpit odor is mainly caused by the following factors: 1, genetic factors: patients with armpit odor often have a family history, so there is a certain relationship with heredity; 2, sweat secretion: the armpit area has parietal secretion sweat glands, after puberty, androgen activity increases, sweat secretion of sweat glands, increased sweat in the armpit area, in addition to the emotional tension, increased activity can also cause local sweating; 3, microbial infections: armpit area contains a large number of bacteria, fungi and other microorganisms, which can decompose the sweat and produce odor. Part contains a large number of bacteria, fungi and other microorganisms, which can decompose the sweat and produce odor.