Acquired factors that lead to the occurrence of bad breath include non-disease factors, disease factors, and it is recommended that people with severe bad breath identify the cause of the disease after a timely consultation and treat accordingly as needed. 1. Environmental and psychological factors. Including food influence, such as eating spicy stimulating food, drinking alcohol can lead to increased secretion of sweat, thus aggravating the manifestation of bad breath; exercise factors, after exercise will lead to increased sweating, thus aggravating the bad breath; emotional factors, emotional tension will also lead to increased secretion of sweat, aggravating the bad breath. 2. Physiological factors. Mainly related to the abnormal secretion function of the parietal sweat glands in the armpit, which will be affected by microbial factors and endocrine factors. Microbiological factors: because the secretion of the parietal sweat gland contains more protein, and the armpit ventilation is poor, will lead to a large number of bacterial growth, bacterial decomposition of sweat will lead to odor. Endocrine factors: after puberty androgen levels increase, will stimulate sweat gland secretion increase, thus producing odor.