Why Do My Feet Always Smell Like Vinegar and Piss?

Ah, friends. They're like family but cooler. Fully customizable. Fall and one of them will be right there to pick you back up. But as great as friends can be, they also do a lot of really stupid stuff. Stuff that blows your mind. Like, sometimes it seems crazy that you even hang out with people who make such crappy decisions. Stuff that, were it to get out, would be mortifying for anyone with even a shred of self-respect. Lucky for your friends, they've got you to ask their deepest, darkest questions for them. And lucky for you, we started this column to answer those most embarrassing of queries.

The situation: Every time your "friend" bares his feet, a cloud of stink envelopes the room. He tries to avoid taking his shoes off around people, whether he's inside someone's house or just hanging by the pool—yeah, it's that bad. Does he just suck at washing his feet or is there something more serious going on?

The reality: It's no surprise that feet stink—they're home to about 250,000 sweat glands. "Your feet are doomed to smell because apocrine glands, like the ones in your underarms, produce perspiration on the soles of your feet," says Leslie Campbell, a podiatrist and member of the American Podiatric Medical Association.

Two types of bacteria may cause this foul-smelling condition, also known as bromodosis: Researchers have found high concentrations of staphylococcus epidermidis and bacillus subtilis on the plantar skin—or foot skin—of people who suffer from it. These bacteria mingle with sweat and cook up the debilitating stench you know all too well.

When your friend sticks his sweat-factory feet in the warm, dark environment of closed-toe shoes, it creates the perfect conditions for bacteria to grow, mix with sweat, and create one wicked stench. And once the insoles of shoes soak up the perspiration, it can be nearly impossible to escape the odor, Campbell says.

The worst that could happen: Does your friend have extra clammy hands and overly sweaty pits, too? Then his problem could be rooted in hyperhidrosis, an overactive sweat gland disorder that affects 2.8 percent of the population, usually on the hands, feet, and armpits. The downside: This condition can't be cured, Campbell says. The upside: It's far from life-threatening, and it can be managed. People with diabetes are also more prone to fungal infections like athlete's foot, a type of ringworm characterized by red, itchy, cracking skin and bad odor—so if your friend is having other diabetes symptoms he should consider getting checked out.

What's probably happening: Your friend could just be a dirty dude. Let's go back to basics: Feet sweat, so failing to wash and dry them properly every day gives bacteria more opportunity to flourish, Campbell says. The smell could come from poor foot hygiene or not changing into fresh, clean socks and shoes frequently enough, especially after intense activity. Rashes, peeling skin, yellowing nails, or wet-looking skin—imagine the white, wrinkly appearance of skin that's been bandaged for a few days—can all signal fungal infections, which also emit odor (and can warrant a trip to the doctor if over-the-counter meds don't seem to help).

What your friend should do: The culprits here are sweat and bacteria, so avoiding the constant dampness of tight-fitting, closed-toe shoes can tame the smell, Campbell says. He might also want to switch to moisture-wicking socks made of synthetic fibers like polyester and nylon, remove the insoles of his shoes so they can breathe and dry out overnight, and use antifungal and odor-absorbing foot powders in his socks and shoes. And it's always important to have a clean base: That means washing his feet thoroughly with soap, drying them completely before pulling on his socks, and tossing any rotten shoes—yes, even if they're his favorite Nikes—since they'll just perpetuate the stink, Campbell says.

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