Your underarms should naturally be about the same shade as the rest of your skin. But sometimes, the skin in the armpits can turn a darker hue. Dark underarms usually aren’t a sign of anything serious, but some people may find them embarrassing — especially during tank top and swimsuit season.

Darkening is often due to a skin condition called acanthosis nigricans (AN). It causes the skin to thicken and darken in folds around the body.

 

Common areas of darkening include

• armpits

• back of the neck

• groin

• elbows

• knees