Stinky feet can be more than a nuisance. They can be a major source of embarrassment. Some people can’t seem to escape giving off that smell, hard as they try. One expert, Jane E. Andersen, a doctor of podiatric medicine and spokeswoman for the American Podiatric Medical Association, sniffs out the causes of foot odor and how to keep the funk at bay.

Ugh, That Smell

There are more than 250,000 sweat glands in each human foot, along with a host of bacteria that live on the skin’s surface. Bacteria break down sweat molecules, with the side effect of creating an acid with that foul smell. If you suffer from malodorous extremities, “you could have more bacteria on the skin than others, or more sweat than others, or a combination of the two,” says Dr. Andersen, who has a private practice in Chapel Hill, N.C.

Some podiatrists believe a tendency for sweaty feet can be hereditary. Many young people outgrow the trait, suggesting that hormones can have something to do with the odor one’s feet produce. “I see fewer adults with the problem than children by far. Not everyone grows out of it, but many do,” Dr. Andersen says.

Those who haven’t outgrown smelly feet likely won’t cure the problem, but they can hold the stink in check.

Ameliorating the Aroma

When the foot sweats, “usually it is trapped inside a shoe, and the sweat can’t evaporate,” the doctor says. This is true of most types of shoes, especially those made with synthetic materials and closed toes. As shoes get worn, dead skin and bacteria can build up inside, holding that pungent smell hostage. Even when a newly scrubbed foot is slipped back in, the stinky bacteria can repopulate in socks and feet.

The first step to taming a scent that won’t go away is seeing a doctor to search for fungus, like an athlete’s foot infection, that can be one of the causes.

Fabrics are key to the solution, Dr. Andersen says. She recommends her patients choose acrylic-blend wicking socks during the warm months or while exercising, and changing them immediately after the activity so the broken-down sweat can’t build up much. In winter, she likes to wear SmartWool, a brand made with Merino wool that helps keep feet dry but warm through rapid evaporation.

Washing socks isn’t enough to eradicate the smell. “If you’re not washing your socks with bleach and hot water, you’re not killing the bacteria and fungus,” the doctor says.

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