Onychomycosis is an infection of the toenail or fingernails.

Fungal Infection of the Toenails
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The infection is caused by a fungus. It can spread to humans from direct contact. This type of fungus lives in warm, moist places such as showers.

Risk Factors

Things that increase the risk of onychomycosis include:


Onychomycosis may cause:

  • Thickened nail that is difficult to cut
  • Brittle or ragged nail
  • Discolored or unsightly nail
  • Pain in the nail with normal use

It may happen in one or more of the nails.


The doctor will ask about and past health. A physical exam will be done. A piece of the nail may be removed for testing. Results make take several weeks.


Onychomycosis can be hard to treat. It may return after treatment. Treatment options include:

  • Antifungal medicine—may be pills or creams and lotions applied to the area
  • Surgery—nail may need to be removed for severe infections

Nails grow slowly. It can take up to a year to clear the nail.


Steps that may lower the chance of onychomycosis:

  • Keep feet clean. Dry them completely after washing.
  • Keep hands dry. Wear rubber gloves when cleaning.
  • Keep nails short and clean. Trim them straight across.
  • Do not trim or pick at the skin near nails.
  • Do not wear shoes that are too tight.
  • Wear cotton socks that can pull moisture away from skin. Change socks if they are damp.
  • Use footwear when walking around swimming pools, locker rooms, and other public places.
  • Avoid artificial nails. They can trap moisture.

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