Gray nails are usually treated with antifungal drugs, but due to the large individual differences in patients with gray nails, there is no absolute best, fastest, or most effective medication, and the most appropriate medication needs to be selected under the guidance of a physician, taking full account of the individual situation. The common cases are as follows: 1. Superficial type: the beginning is often dotted, irregular in shape, with a variable number of dots, and the fungal infection is usually confined to the nail surface. It can be treated by topical medication, such as using amorolfine application, terbinafine ointment, sertaconazole ointment, or topical rubbing with ointments containing salicylic acid and benzoic acid ingredients; 2. Subcutaneous type: The whole nail can be gray and gradually change to yellowish brown until black, followed by nail plate deterioration, nail bed thickening, and fungal infection in the deeper layers of the nail, including the nail bed as well as the surrounding tissues. Because of the limited permeability of topical medications, it is difficult to treat the deep nail tissue as well as the perinail tissue. At this time, the use of topical medications alone cannot achieve the therapeutic effect, and it is necessary to consider the combination of oral medications for treatment. Clinically, oral medications such as terbinafine and itraconazole are usually chosen for antifungal treatment. In addition to drug treatment, if the symptoms are more serious or combined with complications such as nail infection, you need to follow medical advice to remove the diseased nail, and can also use laser treatment and photodynamic therapy to inhibit pathogenic bacteria and kill microorganisms.