Fingernails and toenails can get infected with fungus. A fungus is a kind of plant. Mushrooms, mold, and mildew are examples of fungi. Fungi live in air, in soil, on plants, and in water. Some live in the human body.
Medical terms for the infection are onychomycosis or tinea unguium.
Fungus grows best on warm, damp skin. The fungus that infects the nail usually spreads from infected skin close to the nail. You are more likely to get this infection if you have diabetes or a problem with the immune system. Other risk factors include contact with animals, contact sports, or swimming.
Infected nails are thickened and yellow or brown. They are more brittle than uninfected nails. They may lift, crumble, or flake.
Your healthcare provider will examine the nail. Your provider may take a scraping of the nail and look at it under a microscope for evidence of fungal infection. A sample of the nail may be sent to the lab for tests to identify the specific type of fungus causing the infection.
If the infection is very mild, your provider may prescribe medicine you can put on the nail. For more severe infections, your provider may prescribe an antifungal medicine to be taken by mouth.
You may need to take the medicine until the nail grows all the way out and there is no longer any sign of the fungal infection. This usually takes about 6 months for fingernails and 12 months for toenails.
Fungi grow where it is damp. To keep fungal infections from occurring or to keep them from coming back once they have been treated, it's important to keep your hands and feet as dry as possible. It may help to:
