The yellowing of the toenails with horizontal lines is mostly related to the occurrence of onychomycosis, which can be treated with oral and topical antifungal preparations such as miconazole ointment, terbinafine cream, itraconazole, etc. The treatment of onychomycosis can be done through the use of oral and topical antifungal preparations. Nail fungus, commonly known as “gray nails”, is a fungal invasion of the nail plate or under the nail caused by the disease, the patient will usually have cracked nails, brittle, thickening, if the nail under the keratin deposition, the nails will become cloudy or loose, this time it is necessary to actively antifungal treatment. 1. Topical medication: miconazole ointment, terbinafine cream and other preparations can be used as prescribed by the doctor, and the thickened portion of the diseased nail should be removed if necessary to enhance the effect of drug therapy. 2. Oral drugs: for more serious patients, oral itraconazole or terbinafine and other preparations as prescribed by the doctor. Treatment should also pay attention to wear air permeable shoes, change shoes and socks, do not share slippers and other objects, do not scratch the local hand, eat less spicy and stimulating food. For patients with yellow toenails with horizontal stripes, it is recommended to go to a regular hospital, clear the cause of the disease under the guidance of the doctor active treatment.