Gray nail is the common name for onychomycosis, stubborn onychomycosis should be used externally, internal antifungal drugs comprehensive treatment. For example, use Amorphophallus powder, take itraconazole capsule internally and so on. Gray nails are due to infection with fungus, and the fungus infects the deep nail plate and eventually forms gray nails. 1. Topical medication: Usually, the gray nail should be softened first, and the nail should be removed cleanly with a knife or a nail file to expose the nail bed, and then you can use topical cycloheximide and amorphophallic acid. 2. Oral medication: Simply using external medication to treat onychomycosis is generally ineffective, and should be combined with oral antifungal medication, especially for stubborn onychomycosis, a combination of external and internal medication is recommended. Oral antifungal drugs commonly used itraconazole, terbinafine and so on. You have to insist on continuous use of medication and use enough medication to get a complete cure. The stubborn nail fungus is recommended to go to the hospital in time, under the guidance of the doctor symptomatic treatment, do not self-medication.