Toenail Fungus

What Is Toenail Fungus

Toenail fungus, or onychomycosis, is a fairly common infection underneath the surface of the toenail that affects about 20% of Americans. Typically, it’s caused by tiny fungal organisms called dermatophytes. (Less commonly, the infection can be caused by molds or yeasts.) Once infected, the toenail often darkens and develops white streaks, becomes thick, and gives off an unpleasant odor. Debris may gather beneath the nail as well.

If left untreated, the infection may spread to other toenails, making it hard to walk. The fungal infection can also travel to your fingernails or skin.

What Causes Toenail Fungus

Toenail fungus occurs when any of the following enter your feet through a skin cut or a separation between your nail bed and nail, then grow and thrive:

  • Dermatocytes (a type of fungus)
  • Yeast
  • Mold

Even tiny cuts or separations can let in these microscopic organisms. Most commonly, people pick up the microorganisms in warm, moist places such as:

  • Showers
  • Swimming pools
  • Gyms
  • Public bathing areas
  • Carpet
  • Pedicure salons (through the tools used there)

Risk Factors For Toenail Fungus

Several factors can make people more prone to toenail fungus. These are:

  • Age. With advancing age, blood flow to the feet diminishes, lessening the body’s ability to fight infections there. Older people’s toenails may grow more slowly and become thicker, making them susceptible to invading organisms.
  • Working in a humid place.
  • Going barefoot in moist public areas like shower facilities, swimming pools, and gyms.
  • Sweating heavily
  • Wearing socks and shoes that aren’t well-ventilated and absorbent.
  • Athlete’s foot, which is caused by a fungus that can spread from your skin to your nails.
  • Circulation problems, since less blood flow to the feet interferes with the body’s ability to fight infection.
  • Diabetes and other conditions that weaken the immune system.
  • Psoriasis, a condition that leads to abnormally rapid skin-cell growth and can cause toenails to pit or separate from the nail bed. According to the National Psoriasis Foundation, about a third of people who have psoriasis of their nails also have a fungal infection.
  • A minor cut, injury, or other infection to the feet’s skin or nails.

Diagnosing Toenail Fungus

To following procedures are used in diagnosing toenail fungus:

  • Physical examination. Your doctor will probably want to look at your toenails.
  • Laboratory testing. Your physician may also take a scraping of debris from under your nail, and send it to a lab to be grown in a culture or examined under a microscope, in order to determine whether you have an infection and what organism is causing it.

Symptoms of Toenail Fungus

Though there’s more than one kind of toenail fungus, symptoms are generally similar.

You may have a fungal infection if your toenails are:

  • Flecked with a small white or yellow spot under the tip. This is often the first sign.
  • Dull
  • Brittle, ragged, or crumbly
  • Misshapen
  • Bad-smelling
  • Separating from the nail bed
  • Painful or throbbing toes


Treating toenail fungus can be difficult. The condition is cured by the growth of new, healthy nails, but toenails grow very slowly, which means it can take up to a year for the infection to fully clear. According to the National Institutes of Health, medicines only clear up about half of all cases, and even then, the infection may eventually come back.

Living With Toenail Fungus

Because it can take months for a fungal toenail infection to clear (if it indeed does; half of all cases don’t respond to treatment), you may just have to manage the infected nail.

Here are a few tips:

  • Wash your feet daily. Regular foot washing over a period of several months may make the infection temporarily subside.
  • File down the white markings on your feet to improve appearance and lessen discomfort.
  • Apply an over-the-counter liquid antifungal treatment. This won’t bring permanent improvement, but it will provide temporary relief.
  • Make regular visits to a podiatrist to have the nail cut and filed down (a procedure called debridement). This can help keep an overgrown nail from causing foot irritation.

Depending on the severity of the infection, you and your podiatrist may decide to remove the nail entirely.


Though it is common, toenail fungus is not a disease that is regularly screened for. If you think you have toenail fungus, visit your doctor. She will examine your toenail, and may also take a scraping of the debris beneath it to send to a lab for further testing, and will most likely be able to provide prompt diagnosis and treatment.


Since toenail fungus is so hard to treat, catching it early – or better still, avoiding it in the first place – is important. Regularly inspect your feet and toes, so you spot problems before they become severe.

And practice these healthy habits:

  • Wash your feet with soap and water daily, then dry them completely
  • Keep your nails trimmed so they don’t extend beyond the tips of your toes
  • Avoid picking at or trimming the skin around your toes; they serve as barriers to infection
  • Don’t use artificial nails – they can lock in moisture
  • Change your shoes, socks or hosiery at least every day. Make sure your hose aren’t too tight, which can trap moisture. Consider wearing socks made from synthetic moisture-wicking fibers – they’ll keep feet dryer than cotton or wool socks
  • Wear breathable, comfortable shoes
  • Wear shower shoes when using public showers or pools.
  • Make sure any pedicure tools used on your feet in a salon, or at home, have first been disinfected, including nail clippers
  • If you think a nail is infected, don’t cover it with nail polish
  • If you have diabetes, work with your doctor to keep your blood sugar under control, as diabetes can increase your susceptibility to fungal nail infections

Medication And Treatment

While over-the-counter toenail-fungus medications are available, experts agree they generally aren’t very effective. You physician is more likely to recommend one of these medicines or treatments instead:

  • Prescription antifungals, such as terbinafine (Lamisil) or itraconazole (Sporanox). You’ll typically take a six- to twelve-week course of the medication, but may not see results for months or even a year. If you continue to expose your feet to moist, warm environments, or neglect your foot hygiene, the infection can return.
  • Antifungal nail polish. This lacquer, called ciclopirox (or Penlac), is sometimes used to treat mild or moderate infections. Daily use can sometimes clear up the fungus, but it takes about a year.
  • Topical medicines (medications applied to the skin). These creams are often used along with a special lotion that contains urea, to make them be absorbed more quickly. Your doctor may also file down your nail (a procedure called debridement), to cut down on the problem area. Usually, topicals can’t cure fungus on their own, and are used along with oral medications to boost the latter’s effectiveness.
  • If your toenail fungus is really severe or painful, your doctor may recommend removing the nail. A new, healthier nail will likely grow in, though it may take a year. In the meantime, your physician may also direct you to apply antifungal polish to the nail bed.
  • Photodynamic therapy. This relatively new treatment involves treating the toenail with acid, then exposing it to intense light.

Complementary and Alternative Treatment

Home remedies for toenail fungus haven’t been thoroughly studied, but these two are popular:

  • Vicks VapoRub. Numerous patients have reported good results from rubbing this product onto their infected nails. Ask your doctor whether he thinks it’s worth a try, and if so, how often to apply it.
  • Vinegar. Some studies have shown it can short-circuit the growth of certain strains of bacteria. Foot-care experts often suggest a 15- to 20-minute soak in a mixture of 1 part vinegar to 2 parts warm water, then thoroughly rinsing and gently drying your feet. Ask your doctor if this treatment is safe for you to try.

Care Guide

Stick with your medications. You may need to take them for up to a year before you see results—but they won’t work at all if you don’t keep taking them as directed.

Practice good foot hygiene, including washing your feet with soap and water and drying them daily; wearing breathable and comfortable shoes, socks, and hosiery; and keeping your toenails trimmed. Wear shower shoes in public bathing areas, and make sure that any grooming tools used on your feet have been disinfected beforehand. These steps can help keep your infection from spreading or worsening, and in some cases may even temporarily make it subside. See additional prevention methods here.

When To Contact A Doctor

If you’ve already been diagnosed with toenail fungus, call your doctor if:

  • The infection seems to be spreading
  • You’re experiencing pain in the affected area
  • Your toenail has grown so thick that it’s causing you discomfort
  • The appearance of your nail significantly changes

Occasionally, the affected area can also develop a bacterial infection. If any of these symptoms occur, contact your physician:

  • Red streaks originating from the site of the fungal infection
  • Swelling, redness, increased pain, tenderness, a feeling of heat at the site
  • Oozing pus
  • A fever of 100 degrees F or higher with no other readily identifiable cause of infection

Questions For Your Doctor

Whether your primary care physician focuses on family, internal, or geriatric medicine, talking to him or her is the best place to begin. Your physician can either treat the fungus or refer you to someone who can. Be sure to check with your insurance carrier about which of these professional services are covered. The following health professionals can all diagnose and treat fungal nail infections:

  • Dermatologists
  • Podiatrists


Questions For A Doctor

Knowledge is power when it comes to treating and managing your toenail fungus. Some good questions to ask your doctor include:

  • How severe is my condition?
  • Is it likely to worsen?
  • What is the usual prognosis for people with my type of fungal infection?
  • How might my infection affect my daily life?
  • What type of treatment do you recommend, and why?
  • What are the side effects of the medications or treatments you recommend?
  • Are home remedies worth trying?
  • Could lifestyle changes be helpful in eliminating my toenail fungus, or making it less severe?


April is National Foot Health Awareness Month, founded by the American Podiatric Medical Association. There are a number of online resources for people who want to know more about toenail fungus and foot conditions.

For extensive information on the causes treatments and prevention of toenail fungus, as well as general foot-care tips and a directory of podiatrists, visit: The American Podiatric Medical Association

Interested in the very latest studies and research? Find that, as well as a photo gallery and self-care guidelines, here: The National Library of Medicine’s MedlinePlus website

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