A fingernail or toenail infection that is caused by a fungus is called onychomycosis (say: "on-ee-koh-my-ko-sis"). Toenails are more likely to become infected than fingernails.
Signs of a fungal nail infection include nails that are:
You may also have pain or discomfort in the affected toes or fingers.
Anyone can get a fungal nail infection, but these infections are more common in adults older than 60 years of age. They are especially common in people who have diabetes or circulation problems. Men are more likely than women to get fungal nail infections.
It may be hard to know where or how you got a fungal nail infection. A warm, wet place is a good place for a fungus to grow. If you often wear heavy work boots that make your feet warm and sweaty, a fungus can grow around your toenails. If you often walk barefoot in locker rooms, you can pick up a fungus from the warm, wet floors.
People whose hands are often wet (for example, dishwashers in restaurants and professional house cleaners) are more likely to get fungal fingernail infections.
Sometimes several people in a family will get fungal infections in their nails at the same time. This can happen because their immune systems aren't able to fight off the infection very well or because the infection is being passed when they use the same towels.
If you think you have a fungal infection in your fingernails or toenails, see your doctor. By looking carefully at your nails, your doctor might be able to tell if you have an infection.
To be sure of what kind of infection you have, your doctor might scrape a little bit of tissue from your nail and send it to a lab. The test can tell if you have a fungal infection or another kind of infection.
Several medicines can treat a fungal nail infection. Oral antifungal medicines help a new nail grow to replace the infected nail. You might need to take the antifungal medicine for 6 to 12 weeks. It depends on how severe the infection is. Some of these oral antifungal medicines are not safe for people who have liver problems or a history of congestive heart failure. Be sure to let your doctor know if you have one of these conditions. Your doctor will decide which medicine is right for you.
Topical treatments (creams and polish that you apply to the top of your nail) are also available. However, topical medicines alone usually do not cure fungal nail infections.
Here are some things you can do to take care of your nails if you have a fungal infection:
Treating Onychomycosis by P Rodgers, M.D. and M Bassler, M.D. (American Family Physician February 15, 2001, https://webarchive.library.unt.edu/web/20121006224126/http://www.aafp.org/afp/20010215/663.html)
Written by familydoctor.org editorial staff
Reviewed/Updated: 11/10
Created: 02/01