Nail fungus occurs when a fungus invades the nail of a finger or toe, or the skin under the nail (nail bed). The infected nail often turns yellowish or whitish, and can split and fall apart. Pieces of skin and nail fragments can accumulate under the nail. The nail can also become thick and separate from the skin.
Most infections are caused by the same fungus that causes ringworm of the foot (athlete's foot). You can become infected if you walk barefoot in showers or public swimming pools (swimming pools), or if you share personal items, such as towels or nail clippers. Some people may be more likely than others to get yeast infections.
Nail fungal infections usually do not get better without treatment. Even with treatment, these infections often recur.