Though your nose can’t deny that it’s your foot that exudes the odor, it’s not really the culprit—it’s bacteria!
These single-cell organisms normally inhabit dark and damp places—just like the sweaty creases of your feet trapped inside the shoes you’ve been wearing all day. Want to know what bacteria are doing there? This may sound gross, but they’re actually feasting on your dead skin cells and natural oils! Yes, that’s right—your very own waste materials are actually what they eat to survive.
And the darker, wetter, and warmer the environment gets, the faster they multiply. So the sweatier your feet get, the more bacteria get invited to join in on the buffet. Now here’s the problem: your feet have the capacity of hosting a whole town fiesta as each one has about 250,000 sweat glands—the most number of sweat glands per area in the entire human body! Each foot can produce more than a pint of sweat a day!
So does sweating a lot make your feet smell bad? Well, not quite. Sweat is basically just made up of salt and water, so it really doesn’t have any odor by itself. The stench you smell when you take off your shoes is actually from the waste materials that the bacteria excrete as they devour your foot’s dead skin cells and oils. These waste materials are made up of organic acids that produce a foul odor that emanates as stink in your feet.
For most people, the foul smell isn’t something that can cause panic in a movie house or repel even your most loyal pet. It’s mostly something that would just make your girlfriend’s nose cringe a bit, but she’ll love you nonetheless. For about 10-15 percent of people, however, the stench can be terrible… I mean really the “rotten egg” kind of terrible! This is because these people produce more sweat in their feet than the rest of the population, a condition which attracts bacteria called Micrococcus sedentarius. These guys not only produce organic acids, they also emit volatile sulfur compounds that ooze out a powerfully repulsive odor.