In most cases, the gray nails on the feet can be transmitted to the fingernails, which are also known as onychomycosis, and can be self-infected through direct or indirect contact, so if the patient is not treated in time and the hands and feet are in contact for a long time, it can be transmitted to the hands and cause onychomycosis on one hand, then to both hands, and eventually form onychomycosis on the hands. The first is to take care of your nail fungus on a daily basis. It is important to have good habits to treat this disease, so patients need to exercise in moderation, arrange their life and rest reasonably, and keep their spirits happy in order to enhance their own physical fitness. In addition, if patients have chronic diseases such as diabetes, they should actively control the primary disease to reduce the risk of infection. Second, drug treatment: 1, local drug treatment: mainly used for patients with mild disease or can not tolerate oral drugs, under the guidance of doctors can use amorolfine application, ciclopirox cream and other antifungal drugs applied externally, the course of 2-3 months; 2, systemic drug treatment: currently the clinical use of terbinafine, itraconazole and fluconazole oral administration.