Two nail caps on one finger may be a normal physiological phenomenon, or it may be a nail fungus disease, in which the distal lateral subnail type and total nail destruction type will show similar symptoms. 1. Physiological phenomenon: If one of the parents has two nail caps on the little toe, this condition may appear in the next generation, also called compound nail, which is a genetic inheritance and a normal physiological phenomenon. 2. Nail fungal disease: distal lateral subnail type is a more common type, mostly tinea pedis treatment is not complete spread, dermatophytes will be from one side of the deck, subnail tissue, the main performance is the distal front and side edge of the part of the thickening of gray and yellow turbid nails, similar to the two nail cover. The whole nail destruction type is a more serious manifestation of the disease, when the fungus invades the whole nail plate and nail bed, it will cause the whole nail destruction and thickening, the nail plate is partially lost or completely lost, the surface of the nail bed is left with rough keratinized buildups, it looks like there are two fingernail caps. A finger with two nail caps can go to the hospital and be treated according to the situation.