A Reddit user shared a photo of their nail showing a “black line,” and was quickly advised by other users to see a doctor immediately.
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“Mark on my finger that darkened over time,” the user wrote in the caption of the image, which shows a very dark and thick line on the index finger.
Other users quickly urged the person to seek medical attention. “Take that to a doctor. Unexplained tissue darkening can be serious,” said one commenter.
The man who posted the photo then explained that it “apparently is just a mole” that he’s “had for five years,” but he wondered if he should “get it checked again.”
“A mole that changes in any way should be examined by a doctor 100% of the time,” another user added. “Changes in moles need to be investigated. It doesn’t mean it’s cancer, but it must be checked to ensure it isn’t, or to determine if [the mole] has become precancerous,” warned another.
A medical professional also advised the user to get a check-up, reassuring them that while “not all melanonychia [black or brown lines on nails] are cancer,” when “they change, it’s cause for concern.”
Thicker horizontal lines on the nail are called “Beau’s lines,” and while they are usually harmless, “discoloration of the nail bed can be a symptom of a type of cancer called subungual melanoma,” according to Healthline.
“It usually appears as a dark vertical band (from top to bottom) on the nail. Subungual melanoma is rare, but serious. This type of skin cancer — called acral lentiginous melanoma — is an aggressive form of melanoma,” added the Cleveland Clinic.
Photo: Reddit / Snoo_2076. This content was created with the help of AI and reviewed by the editorial team.
