A fungal nail occurs when a fungus attacks a toenail, a fingernail or the skin under the nail. Any part of the body can be affected by the fungal infections.
According to the American Academy of Dermatology (AAD), toenails are more often affected by the fungal infections than the fingernails, because they are usually confined to the shoes and are in moist, warm environment.
If you are healthy, the fungal infection will not cause any serious problems. But, it can be hurtful, look awful or damage the nails.