Toenail fungus is a condition that disfigures and sometimes destroys the nail. It is also called onychomycosis
Toenail fungus can be caused by several different types of fungi. Fungi are microscopic organisms related to mold and mildew.
These 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
- Practicing poor foot hygiene
- Wearing layers of toenail polish, which doesn't allow the nail to breathe
- Being a military personnel, athlete or miner. This is because toenail fungi may spread from foot to foot on the floors of showers and locker rooms.
- Having a chronic illnesses, such as diabetes or HIV
- Having a circulatory problem that decreases blood flow to the toes
Toenails on the big toe and little toe are the most likely to develop a toenail fungus. This may be partly because the big toe and little toe are constantly exposed to friction from the sides of shoes.
When a toenail develops a fungal infection, it typically turns yellow or brown. It becomes thick and overgrown. Foul-smelling debris also may accumulate under the nail.
As the infection continues, the nail may crumble gradually and fall off. Or, it may become so thick that the affected toe feels uncomfortable or painful inside shoes.
A less common variety of toenail fungus is called white superficial onychomycosis. The nail turns white rather than yellow or brown. The surface becomes soft, dry and powdery.
You will describe your foot symptoms to your doctor. He or she will ask about any factors that may increase your risk of toenail fungus. These include:
- A high-risk occupation
- Sports participation
- Tight-fitting shoes or hosiery
- Poor foot hygiene
- Use of heavy toenail polish
- A history of illness that may decrease your resistance to infection or interfere with blood flow to your toes. These include:
- Poor circulation
Your doctor will examine your affected toenail or toenails. Often the diagnosis can be made based on the appearance of toenails. Your doctor may take small samples of the affected nails. These samples will be sent to a laboratory where they are tested for fungi and other infectious agents.
Toenail fungus rarely heals on its own. It is usually a chronic (long-lasting) condition. It can gradually worsen to involve more and more of the nail. Even if the affected nail comes off, the new nail may be infected with fungus.
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Disclaimer: This content should not be considered complete and should not be used in place of a call or visit to a health professional.