Suddenly smelly feet may be due to poor personal hygiene habits and other physiological factors, and secondly may be related to tinea pedis, sweat and odor and other diseases. 1. Physiological factors: poor personal hygiene habits, shoes permeability and other physiological factors may cause feet suddenly become smelly. 2. Tinea pedis: pathogenic bacterial infection, hot and humid environment and impaired immune function and other factors may cause tinea pedis, patients will appear keratinized scaly skin, itching and bad smell and other symptoms. 3. Sweat odor: abnormal secretion function of the top secretion gland, bacterial decomposition and high temperature and other factors may lead to stinky sweating, the patient’s armpits, soles and areola and other places will appear odor and color sweating and other conditions. There are many reasons why feet suddenly become smelly, and after excluding physiological factors, it is recommended that the patient consult a doctor for examination to clarify the cause of the disease.