Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Causes
By Mayo Clinic staffFungi are microscopic organisms that don't need sunlight to survive. Some fungi have beneficial uses, while others cause illness and infection.
Nail fungal infections are typically caused by a fungus that belongs to a group of fungi called dermatophytes. But yeasts and molds also can be responsible for nail fungal infections.
All of these microscopic organisms live in warm, moist environments, including swimming pools and showers. They can invade your skin through tiny invisible cuts or through a small separation between your nail and nail bed. They cause problems only if your nails are continually exposed to warmth and moisture — conditions perfect for the growth and spread of fungi.
Infection with nail fungus occurs more in toenails than in fingernails because toenails are often confined in a dark, warm, moist environment inside your shoes — where fungi can thrive. Another reason may be the diminished blood circulation to the toes as compared with the fingers, which makes it harder for your body's immune system to detect and eliminate the infection.
- Onychomycosis. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec10/ch125/ch125c.html?qt=nail%20fungus&alt=sh. Accessed June 30, 2009.
- Goldstein A, et al. Onychomycosis. http://www.uptodate.com/home/index.html. Accessed June 30, 2009.
- Nail problems. American Podiatric Medical Association. http://www.apma.org/MainMenu/Foot-Health/FootHealthBrochures/GeneralFootHealthBrochures/NailProblems.aspx. Accessed June 30, 2009.
- Watanabe D, et al. Successful treatment of toenail onychomycosis with photodynamic therapy. Archives of Dermatology. 2008;144:19.
- De Berker D. Fungal nail disease. The New England Journal of Medicine. 2009;360:2108.
- Hinojosa J, et al. Which antifungal is best for toenail onychomycosis? The Journal of Family Practice. 2007;56:581.
