What Is a Fungal Nail Infection?
A fungal nail infection is a common condition that can leave you with brittle, discolored nails, usually on your toes.
Its formal name is onychomycosis, and it’s a lot like athlete’s foot. But instead of affecting the skin on the bottom of your feet or between your toes, it invades your nails.
Fungi are tiny organisms you can only see through a microscope. Many different types can cause a nail infection. Sometimes they live on your skin and don’t make any trouble. But if you have a lot in one area, you might get infected.
Don’t be embarrassed if you have toenail or fingernail fungus. It’s way more common than you think.
Types of Fungal Nail Infections
There are 4 main kinds of fungal nail infection. Each looks slightly different:
- Distal or lateral subungual onychomycosis. This is the most common kind. It results from a fungus called a dermatophyte. You can get it in your fingernails or toenails. It starts in the nail bed, underneath the nail. You’ll see a yellowish colored area that spreads from the edges of the nail to the center, and places where it comes apart from the nail bed.
- White superficial onychomycosis. This is less common and only affects the nail surface, mainly on your toenails. It starts as white spots, which become powdery and cause the nail to crumble.
- Proximal subungual onychomycosis. This appears first as white spots in the center of the nail bed at the cuticle. They move outward as the finger or toenail grows. It’s rare and usually affects people who have immune system problems, like HIV infection.
- Candidal onychomycosis. Yeast causes this infection that usually affects your fingernails. The area around the nails is often swollen and inflamed, and the nails may come off entirely. It tends to happen to nails that have been damaged by an injury or another infection.
A fungal nail infection occurs when a fungus attacks a fingernail, a toenail, or the skin under the nail, called the nail bed. Photo credit: iStock/Getty Images
Fungal Nail Infection Symptoms
Symptoms are different, depending on which type of fungal nail infection you have. They usually start mild and get more serious.
- At first, you may only see a white or yellow spot under your nail. Over time, this spreads and can turn your whole nail white, yellow, green, or black.
- The nail may thicken and could be hard to trim.
- It may start to curl up or down or loosen from the nail bed.
- Your nail could become brittle and crumble when you touch it.
- Your nail may become misshapen.
- You may notice a bad smell.
It’s easy to ignore fungal nail infections at first, since you may not have any pain. But if you don’t treat them, it can hurt to put any pressure on the area. If an infection gets bad enough, it could even become hard to walk.
Fungal Nail Infection Causes
You get an infection when a crack in your nail or the skin around it allows fungus to get inside and grow.
Since fungus thrives in dark, warm places, your toenails are more likely to be affected than your fingernails. Your toes also have less blood flow than your fingers, which makes it harder for your body to pick up on and prevent an infection.
You’re more likely to get a fungal nail infection if you:
- Are a man
- Are older, since nails become more brittle and likely to crack as you age
- Have a weak immune system or ongoing health problems like diabetes
- Wear shoes that make your feet hot and sweaty
- Walk barefoot through gym showers, swimming pools, and locker rooms –places where fungus spreads easily
- Live with someone who has a fungal infection
- Have athlete’s foot, as the fungus that causes it can spread to your nails
- Recently had an injury or surgery on your nail, or had a previous infection
- Wear plastic gloves or keep your hands wet for long periods
See your doctor if you think you have nail fungus. You may need a prescription to treat it, whether that means taking a medicine by mouth or using a special cream. In serious cases, your nail may need to be removed so a healthy new one can grow in its place. Doctors can also use lasers to treat nail fungus.
Fungal Nail Infection Treatment
See your doctor if you think you have nail fungus. It can be tough to get rid of, and you’re more likely to have success with a prescription. Treatments include:
- Oral antifungals. The doctor may give you a pill to kill fungus in your whole body. This is usually the best way to get rid of a nail infection. Treatment may last 2 months for an infection in your fingernails, or 3 months if it’s in your toenails.
- Topical antifungals. You rub or brush these medicines onto your nails. They may work for a mild infection, but they can’t get deep enough into the nail to cure a more serious one. You might use a topical treatment in combination with a pill.
- Surgery. If other treatments don’t work, the doctor may need to remove your nail entirely and let a healthy one grow back in its place. The new nail could also get infected.
- Laser or photodynamic therapy. Doctors are studying newer treatments that use special light to try to kill the fungus.
Fungal Nail Infection Prevention
To prevent an infection, wash your hands and feet often. Use soap, and make sure you get between your fingers and toes. Also:
- Keep your fingernails and toenails short and trimmed straight across.
- Wear socks that wick away (absorb) moisture. If your feet sweat a lot, change your socks once or twice a day, or take off your shoes and let your feet cool when you have the chance.
- Use antifungal powder or spray on your feet as well as in your shoes. Throw away old pairs of closed-toe shoes since fungi might be living in them.
- If you get manicures at nail salons, visit only the ones that disinfect tools after each client. You can also bring your own file and clippers from home. Ask that your cuticles not be cut, since this can cause tiny breaks in the skin that let germs in.
- Don’t share towels if someone else in your family has nail fungus. This will pass around the infection.
Fungal Nail Infection Complications
It can take a year or more for your nails to look like they did before the infection. And you may continue to have problems:
- The fungus can come back.
- Your nails may be permanently discolored or misshapen.
- The infection may spread to other parts of your body.
It’s especially important to take care of a fungal nail infection if you have diabetes. You’re at greater risk of getting a serious skin infection.