Gray nails are still not well can usually continue to take terbinafine tablets, but the specific treatment time needs to be decided according to the disease, the patient’s health condition and so on. “Gray nails” is the common name for onychomycosis, a disease caused by fungi such as dermatophytes that invade the nail plate and subnail tissues. Oral terbinafine is one of the systemic treatments for onychomycosis, which inhibits ergosterol synthesis in the cell membrane of the fungus and acts as a fungicide. The general course of treatment is 6-9 weeks for finger nail fungus and 12-16 weeks for toenail fungus. This kind of drug is mainly metabolized by liver and kidney, so it is forbidden for people with severe liver and kidney insufficiency or allergy, and should be used with caution for people with liver and kidney insufficiency, children under 2 years old or pregnant women, and adverse reactions such as nausea, abdominal distension, abdominal pain and other gastrointestinal tract reactions or liver enzyme elevation may occur after taking this drug. It is recommended that patients go to the hospital, according to the situation of onychomycosis and personal health conditions to develop a reasonable treatment program, the drug should be used in accordance with the doctor’s instructions, not blindly self-medication.