Black vertical stripes on the inside of the nails see a dermatologist. Black vertical stripes inside the nails are mostly considered to be caused by nail dystrophy and nevus of the mother of nails, which are usually manifested on the nails and belong to the category of dermatology, and need to go to the dermatology department of the hospital for consultation and treatment. In general, nail dystrophy can be caused by a variety of factors, such as congenital ectodermal dysplasia, heredity, psoriasis, lichen planus, as well as penicillamine, fluorouracil and other drugs, etc. Often manifested as nail roughness, nail plate longitudinal cracks, nail loses its luster, black vertical stripes, etc., you need to go to the hospital dermatology department to consult, after the diagnosis of active treatment. In addition, nails mother nevus can be caused by vitamin B12 deficiency, acanthosis nigricans, trauma, fungal infections and other factors, can be directly manifested in the nails with black vertical line symptoms, continue to develop the possibility of malignant changes, need to go to the regular hospital dermatology consultation and treatment.