Toenail Fungus – Onychomycosis


What Is It?

Toenail fungus is a condition that disfigures or destroys the nail. It is also called Onychomycosis.

Toenail fungus can be caused by several different types of fungi. Fungi thrive in the dark, moist and stuffy environment inside shoes. As they grow, fungi feed on keratin. Keratin is the protein that makes up the hard surface of the toenails.


Factors that increase the risk of developing toenail fungus include:

  • Wearing tight-fitting shoes or tight hosiery
  • Poor foot hygiene
  • Wearing layers of toenail polish, which doesn’t allow the nail to breathe
  • Being in common areas without shoes
  • Having a chronic illness, such as diabetes or autoimmune disorders
  • Having a circulatory problem

Many people with toenail fungus have no clear risk factors. Toenails on the big toe and little toe are the most likely to develop a toenail fungus.


The toenail will typically turn yellow or brown and can become thick and overgrown. Foul-smelling debris also may form under the nail. As the infection continues, the nail can crumble and fall off. Or, it may become so thick that the affected toe feels uncomfortable or painful.


Your doctor will examine your affected toenail or toenails. Often the diagnosis can be made based on appearance. Your doctor may take small samples of the affected nails and test for fungi and other infectious agents.

Expected Duration

It is rare for this issue to resolve on its own. It is commonly a chronic condition and can worsen to involve more of the nail. Even if the affected nail comes off, the new nail may be infected with fungus.


To help to prevent toenail fungus:

  • Wear comfortable shoes and hosiery that allow your feet some breathing space
  • Wear shoes, sandals or flip-flops in community areas
  • Wash your feet every day. Dry them thoroughly, and use a good-quality foot powder
  • Wear clean socks or stockings every day
  • Keep your toenails trimmed
  • Disinfect pedicure tools before you use them


Treatment may begin with your doctor removing as much of the infected nail as possible. If the infection is mild and limited to a small area of your nail, your doctor may prescribe an antifungal cream or a medicated nail polish. If the infection is in a wider area of your nail, or several nails, your doctor may prescribe an oral antifungal medication. In very severe cases, when toenail fungus is resistant to treatment, it may be necessary to remove the entire nail surgically.


Most people treated with an oral antifungal medicine are cured after a few months. However, the nail may never become clear and normal-looking and the fungus can return.

F. Keith Nebeker DPM
10463 Double R Blvd, Suite 100
Reno, NV 89521
Phone: 775-200-0036
Fax: 775-358-1413
Office Hours

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