As you go about your routine skin-cancer checks to look for abnormal moles or dark spots, there’s one place you probably didn’t think to examine: your fingernails.
According to The Sun, when UK-based manicurist Jean Skinner spotted an unusual mark on a client’s nail, she instantly knew something was off. The customer had a straight, dark vertical stripe running down her nail and requested a polish color that would cover it up.
Subungual melanoma typically shows up on the nail of the thumb or big toe and should be brought to the attention of a doctor immediately.
Some of the former nail salons the client visited suggested the mark indicated a lack of calcium, a blood blister, or a hereditary feature, but Skinner disagreed.
“[I knew it was] melanoma. I didn’t want to frighten her, but I told her she needed to see her doctor immediately,” Skinner wrote on Facebook. “She called me today to tell me that yes, it was a very aggressive melanoma that has already spread to her lymph nodes. Her prognosis isn’t good.”
Although this specific type of skin cancer is rare, it’s serious: According to the Melanoma Research Foundation, subungual melanoma typically shows up on the nail of the thumb or big toe and should be brought to the attention of a doctor ASAP.
The next time you notice something’s off—especially if it’s a fresh streak of color on your nail—don’t try to cover it up with polish; your nails could be telling you something about your body’s health that you don’t want to ignore.