“The most common cause of darkening of the armpits is in the anatomy, the rubbing of the armpits against each other,” says dermatologist Isabel Ballesteros-Mangubat, MD. She explains that, as a rule, anything that traumatizes the skin darkens it. Trauma or irritation alerts your melanocytes, cells that carry the darkening pigments known as melamin. Once stimulated, the melanocytes grow bigger. Consequently, your skin becomes darker.

You may be wondering who is likely to get darker pits. Is it the fair-skinned girl or the morena? Ballesteros-Mangubat explains, “Darker people are more likely to get dark underarms because they have bigger melanocytes. On the other hand, the fairer ones, like blondes or Americans, have very small melanocytes. They may develop trauma and cause their skin to get dark, but skin usually goes back to normal without treatment.”

With that said, browse through the gallery for five common causes of dark underarms.


(First published as “Under Armed” in the “Beauty” section of Good Housekeeping Philippines’ April 2002 issue. Adapted for use in Female Network. Photo by Jakob Montrasio via Flickr Creative Commons.)