Fungal Nail Infections
What is a fungal nail infection?
A fungal nail infection is an infection that occurs when a fungus attacks your fingernail, toenail, or nail bed. Fungi can attack your nails through small cuts in the skin around the nail or through the opening between the nail and nail bed. If you're healthy, the infection probably won't cause serious problems.
What causes it?
Fungal nail infections can be caused by yeasts, molds, and other kinds of fungus.
Fungi grow best in warm, moist places. They can spread from person to person. You can get a fungal nail infection from walking barefoot in public showers or pools or by sharing personal items, such as towels and nail clippers. If you have athlete's foot, the fungus can spread from your skin to your nails.
You can have fungi on your skin without getting a nail infection. If you are susceptible to fungal infections, they tend to return. They can come back even after successful treatment and especially if you don't do something to prevent them.
What are the symptoms?
Symptoms often develop slowly over time. A nail with a fungal infection may:
- Turn yellow, white, or brown.
- Get thicker.
- Crumble or split and may separate from the skin.
A fungal nail infection usually isn't painful. But over time, you may be uncomfortable or even have pain when you wear shoes, walk, or stand for a long time. The fungus could also spread to other nails or your skin.
How is it diagnosed?
To diagnose a fungal nail infection, your doctor will:
- Look at the skin and nails on your hands and feet.
- Ask about your medical history. This includes any previous symptoms of nail damage or fungal nail infections.
The doctor may take a sample of skin and nail fragments from under the infected nail or a sample of the nail itself. Tests to examine the samples include:
- KOH preparation, to find out if the problem is caused by a fungus.
- Other lab tests, such as a fungal culture, may be done to find which type of fungus you have.
If the tests don't show fungi but your doctor still thinks that you have a fungal infection, a nail biopsy may be needed.
How is a fungal nail infection treated?
It may take time to treat a nail infection. You may need to try several treatments to find one that helps. Even when a treatment works, the nail can get infected again.
Treatment often starts with antifungal medicine.
- You can try an over-the-counter medicine that comes in a cream, lotion, or nail polish.
- Your doctor can also prescribe a stronger antifungal medicine that you apply to your nail.
- Antifungal pills give the best chance of curing a severe nail infection. But they may cost a lot. And they can have serious side effects. You will need to see your doctor for regular testing if you take these pills.
- If you have a severe nail infection or the infection keeps coming back, your doctor may remove the infected nail.
If you have diabetes or a weak immune system, your doctor may suggest treating the infection, even if it doesn't bother you.
How can you care for the infection?
For a mild fungal nail infection, try an antifungal cream, gel, or polish that you put on your nail. To stop the infection from coming back, keep your nails clean and dry. Change socks often. Don't go barefoot in public places. And try not to share personal things like towels and nail clippers.
How can you avoid fungal nail infections?
There are things you can do to avoid getting a fungal nail infection or having it come back.
- Before bed, wash and dry your feet carefully.
Applying a topical antifungal medicine may help prevent repeat infections.
- Keep your feet and hands dry.
Dry skin and nails are less likely to get infected. Put powder on your dry feet or hands after you take a shower or bath.
- Wear sandals or roomy shoes made of materials that allow moisture to escape.
Let your shoes air out for at least 24 hours before you wear them again.
- Wear socks.
Change them if your feet get damp or sweaty.
- Wear shower sandals in wet public areas, such as locker rooms or showers.
Let them dry between uses.
- Do not share nail files or clippers, socks, towels, or other personal items.
- Avoid injuring your nail.
Cutting nails too short is a common cause of nail injury.
Current as of: November 15, 2021
Author: Healthwise Staff
Patrice Burgess MD - Family Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Ellen K. Roh MD - Dermatology