Fungal nail infection

9 min read

What is a fungal nail infection?

Fungal nail infection is a common problem. Around half of all nail problems are due to a fungal infection.

Fungal nail infection is about four times more common in toenails than fingernails and can involve all or part of the nail, including the nail plate, nailbed and root of the nail.

It usually affects adults, especially men, and becomes more common as you get older.

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nail abnormalities

What are the symptoms?

The most common symptom of a fungal nail infection is the nail becoming thickened and discoloured. The nail can turn white, black, yellow or green.

You will not usually feel any pain at first, but the nail can look ugly and, without treatment, there is a chance the infection will spread and lead to complications such as cellulitis.

Read more information about the

symptoms of a fungal nail infection

What causes a fungal nail infection?

Several types of fungus cause nail infections. For example,

athlete's foot
is a fungal skin infection of the toes that easily spreads to the toenails, and candida is a yeast that can cause an infection of the skin around the nails (usually the fingernails).

There are several factors that increase the risk of a fungal nail infection, such as:

  • wearing shoes that cause hot sweaty feet, or being in a humid environment
  • regular damage to the nail or skin
  • having poor health, or certain health conditions such as

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causes of a fungal nail infection

Treating a fungal nail infection

Treatment is not always needed if your infection is mild.

Otherwise, your doctor may send a clipping of your nail to a laboratory for tests to find out the exact cause of the infection and to rule out other conditions. They will then discuss appropriate treatments with you.

Fungal nail infections can be treated and usually cured, but some types of treatment can take several months to work. The main treatment options are either antifungal tablets or antifungal nail paint.

Antifungal tablets are the most successful treatment but they may cause side effects. You should discuss this with your doctor before deciding which treatment to take.

It is important to ensure you look after your nails properly and practise good foot hygiene to stop the infection returning.

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treating a fungal nail infection

Symptoms of a fungal nail infection

The most common symptom of a fungal nail infection is the nail becoming thickened and discoloured. The nail can turn white, black, yellow or green.

A fungal nail infection is usually painless at first and in most cases fungal nail infections will not cause any further complications. However, if the infection is left untreated it may cause pain and discomfort, but this is rare.

If there is pain in the toenail, this can eventually lead to difficulty wearing shoes and walking. In fingernails, it may cause difficulty writing.

As the infection progresses there can be further symptoms, such as the nail becoming brittle, with pieces of nail breaking off or even coming away from the toe or finger completely.

If left untreated, the skin can sometimes become inflamed and painful underneath and around the nail (the nailbed). There may also be white or yellow patches visible on the nailbed or scaly skin next to the nail.

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how fungal nail infection is treated

Complications of a fungal nail infection

In very rare cases the infection can spread to the skin around the nail, resulting in

(bacterial infection under the skin) or
(infection of the bone).

These complications are slightly more common among older people and people with health conditions such as


Causes of fungal nail infections

There are several causes of fungal nail infections. The most common causes are a fungal skin infection or damage to the nail or skin.

Athlete's foot

Fungal infection in the toenail is most commonly caused by a fungal skin infection, such as

athlete's foot
. Around a third of people with athlete's foot will also have a nail infection.

Athlete's foot usually affects the skin between your toes, causing it to be red, flaky and itchy.

Fungi grow easily in warm, damp environments, so an infection is more likely to happen after wearing sweaty trainers or if you often have hot, sweaty feet.

Other causes

Fingernail infections are most often caused by a yeast called candida. Occupations that involve a lot of handwashing, or having your hands in water a lot, are often the cause of fingernail infections. This is because the skin at the base of your nail can become damaged, and is more likely to become infected.

There is an increased risk of a fungal nail infection for those with certain conditions or health issues, such as:

Other factors that can increase the risk of nail infections include:

  • using artificial (cosmetic) nails
  • nail damage
  • constant nail biting
  • living in a warm and humid climate
  • smoking

Nail infections are more likely to happen with increasing age. Sometimes, there is no obvious cause of an infection.

Treatment for fungal nail infections

You may not need any treatment if your fungal nail infection is mild. However, if you do not treat the infection, there is a chance it will spread to other nails.

Serious fungal nail infections need to be treated. The main treatments are:

  • antifungal tablets
  • antifungal nail paints

Your pharmacist or doctor will advise you whether you need treatment, and if so, which type you need.

Antifungal tablets

Taking antifungal medication in the form of tablets means that the treatment reaches your nail via your bloodstream.

The two medicines most commonly prescribed for fungal nail infection are [terbinafine] and [itraconazole].

These can be very effective in the treatment of fungal infections. However, you may have to take the tablets for several months to ensure that the infection has completely gone. Stopping the medication too early can mean that the infection comes back.

An advantage of the antifungal tablets is that they will clear any associated fungal skin infections, such as

athlete's foot
, at the same time.

However, some people prefer not to treat the infection with medication as side effects can sometimes include:

Antifungal nail paint

If you prefer not to take antifungal tablets, your doctor may suggest you try antifungal nail paint instead.

Nail paint is not considered as effective as the tablets because it has to be painted onto the infected nail and work its way through to the infection. It can be difficult to reach all of the infection.

A fingernail can need around six months of treatment, and a toenail up to twelve months.

Laser treatment

Some private clinics are able to offer laser treatment for fungal nail infections. Current evidence shows that this is a safe treatment with promising results in the short-term.

However, more research is needed into the long-term effects of laser treatment as it is still relatively new.

Foot care during your treatment

During your treatment, you should start to see a new healthy nail begin to grow from the base of the nailbed. This is a sign that the treatment is working. The old infected nail should begin to grow out and can be clipped away over a few months.

Speak to your doctor if you do not begin to see a new nail growing after taking your treatment for two to three weeks. Keep using the treatment until your doctor says it is ok to stop. If you stop the treatment too early, the infection could return.

Foot care tips

During and after your treatment, there are a few steps you can take to help keep the infection at bay, listed below.

  • Keep your feet cool and dry and wear shoes and socks that allow your feet to breathe. Wear clean cotton socks and avoid wearing trainers.
  • Treat athlete's foot with antifungal medicine as soon as possible to avoid spreading the infection to your nails.
  • Clip your nails to keep them short.
  • Use a separate pair of clippers or scissors to cut the infected nail, to avoid spreading the infection to other nails.
  • Wear well-fitting shoes, without high heels or narrow toes.
  • Maintain good foot hygiene.
  • Wear clean shower shoes when using a communal shower.
  • Consider seeking treatment from a podiatrist if thickened toenails cause discomfort when walking.
  • Consider replacing old footwear, as this could be contaminated with fungal spores.

Questions to ask

Emma Supple, podiatrist and podiatric surgeon, explains what she would want to know if she had a fungal nail infection.

How do I know it's a fungal nail infection?

If toenails start to take on a yellowed, crumbly appearance then this may be a fungal infection taking hold.

However, some skin conditions and other medical problems change the appearance of your toenail to look like a fungal infection, so it's important to get a correct assessment and diagnosis. A scraping of the toenail can be taken by your doctor or podiatrist to identify the fungus.

Is it serious?

Fungal infections of the toenails are an unpleasant, common problem but are usually painless and not serious.

How can I treat it?

There are a variety of options available.

Your podiatrist can thin down thickened toenails and make them easier to treat with anti-fungal nail paints. This is a long-term option and has limited success. It takes a lot of perseverance.

Anti-fungal creams can be used to treat fungus around the nails. This is usually a more effective treatment in the early stage, when the fungus first starts to affect the toenails.

Anti-fungal tablets are prescribed by a doctor. They are generally very effective. Once the course of treatment has been completed, the toenail may take several months to improve in appearance, as it takes about 12 months for a toenail to grow completely from base to tip. During the period when the nail is regrowing, use an anti-fungal cream to prevent further infection.

What will happen if I don't treat it?

Over time, the fungus can lead to thickened, discoloured toenails and the infection will slowly spread to other toenails. It also can act as a source of skin fungal infections, such as athlete's foot.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.