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A female asked:

Why is there a vertical black line on my right big toenail?

3 doctor answers6 doctors weighed in
Dr. Jonathan Posner
Podiatry 28 years experience
Trauma: A dark line that runs vertically down the nail can indicate that you might have traumatized the nail matrix(the area where the nail starts growing). Other possibilities are fungus, melanoma and genetics. See your doc for a full evaluation.
Dr. Frank Smith
Podiatry 30 years experience
Usually genetic : Melanonychia striata is a possibility would need a picture also may have just damanged the nail root and could be scar changes that originate at the root level . I would get it check by a podiatrist.
Dr. Emily Altman
Dermatology 29 years experience
Black stripe nail: This could be a mole or freckle in growth center of the nail (matrix), fungal infection of the nail & a melanoma under the nail. Needs a diagnosis. Melanoma is a dangerous skin cancer that needs to be diagnosed & treated as soon as possible to have better chances of a cure. If this is a new pigmented streak, if it is changing (darker, wider, more irregular), please see a dermatologist asap.

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Similar questions

A 41-year-old male asked:

Why do i have a black line on my right big toenail from the top to the bottom of the toenail?

1 doctor answer1 doctor weighed in
Dr. Jeffrey Hoffman
Family Medicine 33 years experience
Recommend consult: consider seeing a dermatologist about this to be sure this is not anything more problematic
Last updated Mar 25, 2020


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