The symptoms of gray nails are usually small depressions or transverse nail grooves that slowly thicken, change color, turn white or yellow or stain, and flake. Gray nails are caused by a fungal infection and are contagious and need to be treated promptly. The treatment is as follows, oral antibacterial drugs, such as itraconazole capsules, terbinafine hydrochloride tablets, etc. You can also use topical drugs, such as amorolfine hydrochloride cream, miconazole nitrate cream, etc. It is also necessary to pay attention to the disinfection of the affected area and to remove the necrotic nail in time.