Foot odor occurs when excess perspiration from your feet soaks the lining of your shoes and socks. Perspiration creates an optimal environment for bacteria which can grow and cause a bad odor.
Sweaty, smelly feet and/or shoes are the most common signs.
People who wear poorly ventilated shoes, synthetic or non-leather boots, or non-wicking socks made of polyester or nylon tend to have persistent foot odor.
Bacteria are the major source of foot odor. Bacteria consume dead skin cells on the feet, which then produce foot odor.