Black vertical lines on finger nails may be caused by lack of trace elements, fungal infections, or onychomycosis, etc. You can take vitamins and iron, antifungal drugs and so on. 1. Lack of nutrition: caused by the lack of certain nutrients in the body, such as the lack of vitamin A and iron, will trigger iron deficiency anemia, often accompanied by weakness, dizziness and headache, dry skin and other symptoms. Oral vitamin A, ferrous succinate, etc. should be taken under the guidance of a physician. 2. Fungal infections: there will also be black vertical lines on the fingernails, the most common is onychomycosis, should be applied in a timely manner to improve the antifungal drugs, follow the doctor’s instructions to take itraconazole, and so on. 3. Nail nevus: due to the melanocyte aggregation into a group, synthesize too much melanin, with the growth of nails mixed into the nail plate, and gradually form black vertical stripes in the nail plate, usually belongs to the benign lesions, don’t need to worry too much, but there are a small number of nail nevus will undergo malignant transformation, become melanoma, need regular review. You should pay attention to the balanced intake of nutrition, take more rest and avoid overwork. The black vertical lines on the fingernail is recommended to consult a doctor in a timely manner, after clarifying the cause of the disease, under the guidance of the doctor for symptomatic treatment, the above drugs need to be used in accordance with the doctor’s instructions.