The medical term for gray nails is onychomycosis, and the first department to be consulted should be dermatology. Onychomycosis is one of the common diseases in dermatology, which refers to the disease caused by the invasion of the nail bed/nail plate by the dermatophytes. Nail fungus is contagious and usually spreads through contact. Clinically, it often manifests as cloudy nails, separation of the nail plate from the nail bed, thickening or discoloration of the nails, and may cause atrophy or even loss of nails, and is often accompanied by onychomycosis, etc. Due to the physiological characteristics of the nails themselves, onychomycosis is not a condition that can be transmitted to the patient. Due to the physiological characteristics of the nails themselves, the treatment cycle of onychomycosis is relatively long, which is difficult for patients to adhere to, and the recurrence rate is relatively high. If you want to go to the hospital for treatment, you need to register for an appointment in advance and bring relevant documents, if you have recently had a treatment process, it is recommended that you bring the relevant medical records, in addition, you can choose loose shoes and socks that are easy to take off, easy to diagnose and treat. Nail fungus is recommended to consult the hospital dermatology department, follow the doctor’s instructions standardized treatment.