The normal male lower body does not have an obvious fishy smell, but generally appears fishy smell, mainly due to lack of hygiene, some men have the habit of masturbation, after ejaculation, coupled with a prepuce, the internal will be stored in the sperm and epithelial cells shed mixture, a long time after the fermentation and fishy smell. Some patients are also circumcised, and if combined with glansitis, there is secretion at the mouth of the foreskin, which will also have a fishy smell. It is also seen in men between husband and wife, after sex there will be secretions left on the glans, not timely cleaning, after a certain period of time, there are bacterial decomposition metabolites appear, it will appear fishy smell. If there is a specific urinary tract infection, there will also be these smells. Therefore, it is recommended that when abnormalities are found, a systematic urological examination is performed, and if it is caused by lack of hygiene, timely cleaning is done, and if there is an infectious disease, it needs to be treated with medication.