A visit to the dermatologist is generally recommended to see vertical lines on the nails, which may be the result of conditions such as onychomycosis, psoriasis, and follicular keratosis. Dermatology is the department used to examine and treat skin diseases, and if a patient has vertical lines on the nails, a visit to the dermatology department is usually recommended. The vertical lines on the nails may be due to onychomycosis, which can be accompanied by symptoms such as cloudy nails and discoloration. Or it may be due to psoriasis, in which the patient may also have symptoms of red, scaly patches on the skin, which may be accompanied by changes in the vertical lines of the nails. Follicular keratosis is also considered to be the cause of the disease, the patient may appear in the skin follicular pimples, or accompanied by nail vertical lines and other symptoms. It is recommended to consult the dermatology department of the hospital, and once the disease is diagnosed, the patient should actively cooperate with the doctor to take relevant treatment measures.