The main reasons for feet emitting a sour odor include not paying attention to personal hygiene, foot odor sweating, tinea pedis and so on. 1. Do not pay attention to personal hygiene: especially in the summer after strenuous exercise, coupled with wearing shoes, socks breathability is not good, can lead to excessive sweating feet. If you don’t pay attention to personal hygiene, don’t often change shoes, socks, don’t often wash your feet, it’s easy to lead to foot dirt and sweat mixed and produce sour odor. 2. Foot odor sweating: usually caused by abnormal secretion of sweat by sweat glands. In the case of sweaty feet, the sweat will be decomposed by the bacteria attached to the surface, and then release fatty acids, resulting in sweat sour odor. 3. Tinea pedis: usually caused by fungal infections, fungi attached to the local skin on the soles of the feet, will break down the local skin cuticle, easy to breed bacterial infections, resulting in feet with sour odor. Usually there are also symptoms such as itching feet. As you can see, feet with sour odor can be caused by physiological or pathological factors, it is recommended to pay more attention to skin cleanliness, if there are symptoms of discomfort in a timely manner to seek medical attention.