Toenail fungus

What it looks and feels like

A fungal nail infection grows slowly under and inside the nail. It often starts at the tip or side of the nail and spreads back. It usually does not hurt at first.

You may notice:

• A nail that turns white, yellow, or brown.
• A nail that gets thick and hard to trim.
• Crumbly or ragged edges.
• A nail that lifts away from the skin under it.
• Pressure or pain in shoes once the nail gets very thick.

Other problems, like an old injury or psoriasis, can make nails look much the same. That is one reason it helps to have a doctor take a look.

Common causes

Fungus likes warm, damp places. You are more likely to get a fungal nail if you:

• Have athlete's foot, which can spread to the nails.
• Walk barefoot in locker rooms, pools, or shared showers.
• Wear sweaty shoes and socks for long hours.
• Have hurt the nail before.
• Are older, or have diabetes or poor circulation.

What you can do at home

Home care can help keep the infection from spreading and keep it from coming back:

• Keep feet dry. Dry well between your toes after a shower. Change socks when they get damp.
• Let shoes air out. Switch between pairs so each one can dry.
• Wear sandals in shared spaces. Use shower shoes at the gym and pool.
• Use your own tools. Do not share nail clippers or files.
• Treat athlete's foot. Itchy, peeling skin between the toes can spread fungus to the nails.

Store-bought nail products may help some mild cases. Thick nails are often hard to treat this way.

When to see us

Make an appointment if:

• Your nails are getting thicker, darker, or more brittle.
• Thick nails hurt in your shoes or are hard to trim.
• The skin around the nail is red, swollen, or draining.
• You are not sure if it is fungus or something else.
• You have diabetes or poor circulation. Thick nails can press into the skin and cause a sore. Learn about diabetic foot care.

How we treat it

The right care depends on how many nails are affected, how thick they are, and your overall health. Your doctor may:

• Check whether it is really fungus. This may mean taking a small sample of the nail.
• Trim and thin thick nails, so shoes feel better and treatment can reach the nail.
• Suggest a medicine you put on the nail, or one you take by mouth. Your doctor will go over the pros and cons with you.
• Share tips to help keep the fungus from coming back.

Ask us whether laser treatment is an option for you.

Nails grow slowly. Even when treatment works, it can take many months for a clear nail to grow out. Fungus can also come back, so good foot habits matter.

What a visit looks like

1. We listen. Your doctor asks how long the nails have changed, and what you have tried.
2. We look at your nails and skin. We check your toenails and the skin between your toes.
3. We check what it is. Your doctor may take a small nail sample to confirm the cause.
4. You leave with a plan. You will know your treatment choices and what to expect over the coming months.

It helps to come with bare nails, with no nail polish. That way your doctor can see the whole nail.

New here? Read what to expect at your first visit and fill out your new patient forms ahead of time.

Questions people ask

This page is general information, not medical advice. For advice about your own feet, talk with your doctor.