Clotrimazole ointment is able to treat gray nails. If you want to treat your gray nails completely, it is recommended that you take oral antifungal medication, such as itraconazole capsules or terbinafine hydrochloride tablets. The specific diagnosis is to go to a regular hospital and have a fungal test done, if the fungus is positive in order to clearly diagnose the nail fungus, also known as gray nail. The actual diagnosis of nail fungus can be made by taking antifungal medication afterwards, because the medication has a certain effect on the liver and kidneys, and the clinician will give reasonable treatment after comprehensive evaluation.