Everybody's familiar with stinky feet. Most of us have a friend or relative -- or maybe it's you -- who can clear out a room when they kick off their shoes. Even the sweetest-smelling person can do a decent job stinking up a pair of shoes by running a few miles in them. So what's going on here? Why do your feet have a stronger odor than, say, the palms of your hands, or other parts of your body? After all, isn't body odor about sweat?
Eau de foot is about sweat, yes. A stinky foot may also be a sweaty foot. Each of your feet has 26 bones, 33 joints, 107 ligaments, and 19 muscles -- and as a pair your feet have 250,000 sweat glands that make about one cup (about half a pint) of sweat every day. That means your feet produce more sweat per square inch of skin than any other part of your body [sources: Foot.com, Brawley]. But most of the time sweat itself actually isn't the problem, at least not when it comes to the kind of sweat you find on your feet. You see, there are two types of sweat glands on your body: apocrine glands and eccrine glands. Apocrine glands are found near hair follicles (so you'll find them in abundance on your scalp and in your armpits, as well as the groin region). The sweat they secrete -- a yellowish, thick fluid -- happens in response to stresses. Body odor is the byproduct of bacteria on your skin digesting the sweat produced by apocrine glands. But there are no apocrine glands on your feet.
Eccrine glands, on the other hand, are located in the skin all over your body, including your feet. This sweat is intended to cool you down. On its own, the sweat produced by the eccrine glands on the soles of your feet is pretty much just water and salt, and really doesn't have any odor at all.
It's bacteria that's the real culprit behind foot odor; well, that and whether or not you wear socks.