Fungal nail infection

Overview

A fungal nail infection (also called onychomycosis) is an infection of the nail caused by tiny organisms called fungi (yeast or mold). It usually makes the nail thick, discolored (yellow, white, or brown), and brittle. It often starts at the edge of the nail and can spread to other nails.

Yes, fungal nail infections are very common. They affect about 1 in 10 people at some point in their lives.

Anyone can get a fungal nail infection, but they are more common in older adults, people with diabetes, those who have poor circulation, people who wear tight or non-breathing shoes, and people who often have sweaty feet.

Symptoms

Common symptoms

• Thickened, discolored nail (yellow, white, brown, or greenish)
• Brittle, crumbly, or ragged nail edges
• Nail that has separated from the nail bed (onycholysis)
• Foul odor from the nail
• White or yellow streaks on the side of the nail
• Pain or discomfort when wearing shoes

Symptoms in children

• Similar to adults, but often less noticeable – the nail may just look a little thicker or have a slight color change
• Children may be more likely to have a mild infection that clears on its own

Symptoms in older adults

• Nails are often thicker and more brittle due to age, making infection easier to miss
• More likely to have multiple nails infected at the same time
• Healing may take longer because of slower nail growth and circulation

Causes

Main causes

• Tiny organisms called fungi (most often dermatophytes, but also yeasts and molds) grow on the nail and the skin under it.
• Fungi thrive in warm, damp environments like sweaty shoes, public showers, and swimming pool areas.

Risk factors

• Wearing tight or non-breathing shoes for long periods
• Having sweaty feet or hands
• Walking barefoot in public places like locker rooms, gyms, and pool decks
• Having a minor injury to the nail or skin around it
• Having diabetes, a weakened immune system, or poor blood circulation
• Living with someone who has a fungal infection

When to see a doctor

See a doctor urgently if:

• If you notice signs of a bacterial infection such as increasing redness, swelling, warmth, or pain around the nail, or if you have a fever – seek urgent medical care.

Book a routine appointment if:

• If your nail looks different (thick, discolored, brittle) and it bothers you or doesn't get better with self-care after a few weeks.
• If you have diabetes, poor circulation, or a weakened immune system – it's best to see your doctor early.

Diagnosis

A doctor can often diagnose a fungal nail infection just by looking at your nails. They may also take a small clipping or scraping of the nail to send to a lab for testing to confirm the fungus and rule out other conditions.

Tests that may be done

• Visual examination of the nail
• Nail clipping or scraping for a laboratory culture (growing the fungus) or microscopy (looking under a microscope)
• Sometimes a skin test or blood test if the doctor suspects other causes

What to expect at your appointment

The doctor will examine your nails and ask about your symptoms and any health conditions you have. Taking a nail sample is quick and painless – they will trim a small piece or scrape some debris from under the nail. Results may take a few days to a couple of weeks.

Treatment

Fungal nail infections can be treated, but they often take weeks to months to clear because the nail grows slowly. Treatment depends on the type of fungus, how many nails are affected, and your overall health. Your doctor will recommend the best approach for you. Do not use over-the-counter antifungal products without consulting a healthcare provider if you have diabetes or circulation problems.

Self-care at home

• Keep your nails trimmed short and file down thick areas – but be careful not to injure the skin around the nail.
• Wear clean, dry socks and change them daily. Choose shoes that let your feet breathe (like leather or mesh).
• Dry your feet thoroughly after washing, especially between your toes.
• Avoid sharing towels, nail clippers, or shoes with others.
• Use an antifungal powder or spray on your feet and inside your shoes (ask your pharmacist for a suitable product).

Medical treatments

Medical treatments include antifungal medications taken by mouth (tablets) or applied directly to the nail (medicated nail polish or cream). Treatment usually lasts several weeks to months. In some cases, your doctor may recommend laser therapy or a special medicated solution that you apply daily. Treatment choice depends on your health and the severity of the infection.

When is surgery considered?

In rare and severe cases, if the infection is very painful or has not responded to other treatments, a doctor may remove part or all of the nail (nail avulsion). This is usually done with local anesthetic and allows a new healthy nail to grow.

Living with this condition

Living with a fungal nail infection can be frustrating because it takes time to get better. Be patient with treatment and continue good foot care even after the infection clears to prevent it from coming back.

Lifestyle tips

• Wear clean socks every day, and let your shoes dry out between wears.
• Use antifungal sprays or powders in your shoes as a preventive measure.
• Trim your nails regularly and keep them clean.
• Avoid walking barefoot in public places – wear flip-flops in locker rooms and pool areas.

Diet and exercise

A balanced diet rich in vitamins and minerals supports your immune system. Exercise helps maintain good blood circulation, which can promote nail health. There's no specific diet that cures fungal nail infections.

Mental health and emotional wellbeing

Fungal nails can make people feel embarrassed or self-conscious, especially in social situations or when wearing open-toed shoes. Remember that it is a very common condition and treatable. If it affects your mood or confidence, talk to your doctor or a trusted friend. You are not alone.

Prevention

You can lower your risk of getting a fungal nail infection by keeping your feet clean and dry, wearing breathable shoes, changing socks daily, avoiding walking barefoot in public places, and not sharing nail clippers or towels. Treat athlete's foot promptly, as it can lead to nail infection.

Vaccines

There are no vaccines for fungal nail infections.

Screening programmes

Routine screening is not recommended, but if you have diabetes or a weakened immune system, your doctor may check your feet regularly as part of your care.

Complications

If left untreated

• The infection may spread to other nails or to the skin (athlete's foot).
• In people with diabetes or poor circulation, the nail area can become a site for a secondary bacterial infection (cellulitis).
• Rarely, a severe infection can cause permanent damage to the nail bed.

Long-term outlook

With appropriate treatment, most fungal nail infections improve or clear completely. It can take several months for a new, healthy nail to grow out. Recurrence is possible, especially if you have a tendency to get them. Good foot hygiene and following your treatment plan give you the best chance of success.

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