Toenail Fungus

With toenail fungus, your nail becomes thick and yellow and may show white spots and streaks. A type of mold called a dermatophyte causes tinea unguium, the most common nail fungus. Tinea unguium most frequently targets your toenails, but it can also affect your fingernails. Onychomycosis is another name for the condition.


What is toenail fungus?

Toenail fungus is a widespread fungal infection that affects your toenails. Less commonly, nail fungus can infect your fingernails. Toenail fungus happens when fungi get between your toenail and your toenail bed (the tissue right underneath your toenail). This usually happens through a crack or cut in your toe.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

What is tinea unguium?

When a dermatophyte causes toenail fungus, the condition is called tinea unguium. A dermatophyte is a mold that needs a protein called keratin to grow. Keratin is the main structural material of your nails that makes them hard. Dermatophytes cause 90% of toenail fungal infections. Tinea unguium is also known as onychomycosis.

Who does toenail fungus affect?

Anyone can get toenail fungus. It often affects older adults, especially people over 60.

You may have a higher risk of getting toenail fungus if you have:


How common is toenail fungus?

Toenail fungus is very common, especially as people start to age. Medical experts estimate that onychomycosis affects 1 in 10 people overall. That number jumps to 1 in 2 (50%) for people older than 70.

Symptoms and Causes

What does tinea unguium look like?

Tinea unguium can change your toenail’s appearance in more than one way. Your toenail may:

  • Change color, looking white, yellow or brown.
  • Look chalky or cloudy in some spots.
  • Thicken and possibly look misshapen.
  • Separate from your nail bed (leaving space between your nail and the skin underneath).
  • Crack or break in one or more spots.


Is toenail fungus painful?

Not typically. Toenail fungus can be unsightly to look at, but it usually isn’t painful.

What causes tinea unguium?

A type of mold called a dermatophyte causes tinea unguium. Dermatophytes are fungal microorganisms (too tiny to see with the naked eye). They feed off of keratin, a protein found in your fingernails and toenails. Keratin makes nails hard.

Dermatophytes are the cause behind 90% of toenail fungal infections. But other types of fungi can infect your toenails as well.

Is tinea unguium contagious?

Yes, many types of toenail fungi, including tinea unguium, are quite contagious. You can spread the fungus to someone else through direct contact. You can also get toenail fungus by touching an infected surface.

What are common ways you can get toenail fungus?

Nail fungi like warm, moist, dark places. You can get toenail fungus by:

  • Walking around the perimeters of swimming pools.
  • Using a public locker room or shower.
  • Walking barefoot in a public area.

Can toenail fungus spread to other areas of your body?

Yes. But toenail fungus usually doesn’t spread beyond your toe.

Some dermatophyte fungi spread easily to your skin. (Your skin and scalp also contain keratin.) When dermatophyte fungi affect your skin, the condition is called ringworm.

Toenail fungus may spread to:

  • Other toenails.
  • Skin between your toes (called athlete’s foot).
  • Groin area (called jock itch).
  • Scalp (skin on top of your head).

Diagnosis and Tests

How is toenail fungus diagnosed?

Your healthcare provider will first look closely at the affected toenail to evaluate your symptoms. They may be able to identify toenail fungus simply by looking at your toe. However, your provider may order tests to confirm a fungal infection.

What tests will be done to diagnose toenail fungus?

Your healthcare provider will probably take a small sample from underneath your nail to further analyze it. Viewing the cells under a microscope can confirm a toenail fungus diagnosis. If the initial test is negative, a scraping can be sent to see if the fungus grows out in a culture. This also helps your healthcare provider identify the type of fungus.

Management and Treatment

How is toenail fungus treated?

Toenail fungus is notoriously tricky to treat. You may need to treat tinea unguium for several months to get rid of the fungus. Still, toenail fungus often comes back.

A skin specialist (dermatologist) or foot doctor (podiatrist) can explain your treatment options. If you have a mild case that doesn’t bother you, your healthcare provider may recommend no treatment.

Tinea unguium treatment options include:

Oral antifungal medication

You can take a prescribed oral antifungal medication to treat the fungus. Options include terbinafine (Lamisil®), itraconazole (Sporanox®) or fluconazole (Diflucan®). You’ll need to take the medication every day for several months (or longer). Your healthcare provider may use blood tests to check for potential medication side effects. These medications can affect your liver and interact with other medications, so oral antifungals aren’t for everyone.

Topical medication

You can regularly apply a topical medication right onto your nail. The medication treats the fungus over time. Topical medications are most effective when paired with oral medications.

Laser treatments

Your healthcare provider will direct a high-tech laser beam and special lights at your toenail to treat the fungus. Lasers are U.S. Food and Drug Administration (FDA) approved for “temporary increase of clear nail” in nail fungus, but they’re not a cure. Cure rates for laser treatment are lower than oral and topical mediations. Your healthcare provider won’t typically use lasers as first-line treatments for nail fungus.

What is the most effective treatment for toenail fungus?

The most effective toenail fungus treatment for you will largely depend on your symptoms and situation. Your healthcare provider will consider several factors before recommending a treatment plan. They’ll customize a treatment plan for you.

Overall, oral antifungal medications may offer the most treatment potential. Pairing oral drugs with topical antifungal medication may make treatment more effective.


How can I prevent toenail fungus?

There’s no way to guarantee you won’t get toenail fungus. But you can take several steps to help prevent it:

  • Avoid going barefoot in communal areas such as public showers, locker rooms and swimming pools. Most people pick up fungus in these situations. It helps to wear flip flops in these public areas.
  • If you have a family member with foot fungus or nail fungus, try to use a different shower or wear flip flops in the shower to avoid coming in contact with it.
  • Trauma due to accidental or aggressive clipping of the nails can turn into portals of entry for the fungus.
  • Clean your nail trimmer before using it.
  • Don’t tear or rip your toenails on purpose.
  • If you have diabetes, follow all foot care recommendations from your healthcare provider.
  • Keep your feet dry. Make sure to fully dry your feet after a shower.
  • Soak toenails in warm water before cutting them. Or you can cut your nails after a shower or bath.
  • Trim toenails straight across (don’t round the edges).
  • Wear shoes that fit correctly. They shouldn’t be too loose or tight around the toes.

Outlook / Prognosis

What can I expect if I have a toenail fungus?

While toenail fungus is common, it’s usually not harmful. Symptoms mostly affect the look of your toenail.

Toenail fungus may spread to the skin between your toes or other areas of your body. When getting dressed, put your socks on first to reduce the chance of spread.

Treating toenail fungus takes a long time, and it doesn’t always work. Even then, toenail fungus often returns. Discuss the pros and cons of treating toenail fungus with your healthcare provider to determine what’s best for you.

Practicing good hygiene and foot care reduces the chance toenail fungus will come back. If you have diabetes, getting regular foot exams may help you address foot problems before they get serious.

Living With

Can I wear nail polish if I have toenail fungus?

You may feel tempted to cover up a discolored toenail with nail polish. But if you’re using a topical antifungal, you probably shouldn’t use polish. Your healthcare provider may tell you not to wear it in any case.

Nail polish traps in moisture from your nailbed (the tissue below your toenail). Because fungi thrive in moist environments, wearing nail polish may make a fungal infection worse. However, your nail continues to grow with or without polish.

When should I see my healthcare provider?

In rare cases, toenail fungus can cause an infection called cellulitis. Without prompt treatment, cellulitis may pose a serious danger to your health.

You should seek treatment guidance from a trusted healthcare provider if you have:

  • Circulation problems.
  • Diabetes.
  • Redness, pain or pus near your toenail.
  • A weakened immune system.

What questions should I ask my healthcare provider?

If you have toenail fungus, you may find it helpful to ask your healthcare provider:

  • What type of infection do I have?
  • Do you recommend I treat it? Why or why not?
  • How long will I need treatment?
  • What steps can I take to stop it from coming back?
  • Should I be aware of any potentially serious complications or treatment side effects?

A note from Cleveland Clinic

Toenail fungus (tinea unguium) is an incredibly common infection that can be difficult to treat. Tinea unguium usually isn’t painful, but it may make you feel self-conscious about how your foot looks. If it bothers you, talk to your healthcare provider about your treatment options. A trained specialist (such as a dermatologist or podiatrist) can provide guidance on what’s most likely to address your concerns while protecting your overall health.

Medically Reviewed

Last reviewed on 08/11/2022.

Learn more about our editorial process.

Questions 216.444.2538