Clinically used drugs can be categorized into two types, one is internal, applicable to the case of a large number of diseased nails, usually terbinafine hydrochloride tablets, itraconazole capsules and so on. Topical medicines are suitable for those who do not have a lot of diseased nails, generally there are amorolfine hydrochloride application, compound povidone-iodine application, amorolfine hydrochloride cream and so on. All of these medicines are very effective in treating gray nails. Gray nails are caused by fungal infection, which is contagious and needs timely treatment.