Melanoma under the nail, called subungual melanoma, appears as a dark stripe in a nail that hasn’t had any other trauma—usually, but not always, in the big toe or thumb. While it only accounts for about 3 percent of melanoma cases in Caucasians, it represents as much as 35 percent in dark-skinned people. It’s very aggressive and spreads quickly, so give your nails a thorough once-over at least every 1-3 months—without polish on!
READ MORE: Why It’s Time to Take off Your Toenail Polish
