Nail fungus is a common condition that begins as a white or yellow spot under the tip of your fingernail or toenail. As the fungal infection goes deeper, nail fungus may cause your nail to discolor, thicken and crumble at the edge. It can affect several nails but usually not all of them.
If your condition is mild and not bothering you, you may not need treatment. If your nail fungus is painful and has caused thickened nails, self-care steps and medications may help. But even if treatment is successful, nail fungus often comes back.
Nail fungus is also called onychomycosis (on-ih-koh-my-KOH-sis) and tinea unguium. When fungus infects the areas between your toes and the skin of your feet, it’s called athlete’s foot (tinea pedis).
What are the Symptoms? You may have nail fungus — also called onychomycosis (on-ih-koh-my-KOH-sis) — if one or more of your nails are:
- Brittle, crumbly or ragged
- Distorted in shape
- Dull, with no shine
- A dark color, caused by debris building up under your nail
- Infected nails also may separate from the nail bed, a condition called onycholysis (on-ih-KOL-ih-sis). You may feel pain in your toes or fingertips and detect a slightly foul odor.
When to see a doctor
You may want to see a physician if self-care steps haven’t helped. Also see a doctor if you have diabetes and think you’re developing nail fungus.
What are the causes
Nail fungal infections are typically caused by a dermatophyte fungus. Yeasts and molds also can be responsible for nail fungal infections.
What are fungi?
Fungi are microscopic organisms that don’t need sunlight to survive. Some fungi have beneficial uses. Others cause illness and infection. Fungi:Live in warm, moist environments, including swimming pools and showers Can invade your skin through cuts so tiny you can’t even see them or through a small separation between your nail and nail bed Can cause problems if your nails are often exposed to warm and moist conditions Toenails vs. fingernails Nail fungus occurs more often in toenails than in fingernails, partly because:Toenails often are confined in a dark, warm, moist environment — inside your shoes — where fungi can thrive Toes usually have less blood flow than do fingers, making it harder for your body’s immune system to detect and stop infection
Factors that can increase your risk of developing nail fungus include:
- Being older, owing to reduced blood flow, more years of exposure to fungi and slower growing nails
- Perspiring heavily
- Being male, especially if you have a family history of nail fungal infections
- Working in a humid or moist environment or in a job where your hands are often wet, such as bartending or housekeeping
- Wearing socks and shoes that hinder ventilation and don’t absorb perspiration
- Living with someone who has nail fungus
- Walking barefoot in damp communal areas, such as swimming pools, gyms and shower rooms
- Having athlete’s foot
- Having a minor skin or nail injury or a skin condition, such as psoriasis
- Having diabetes, circulation problems, a weakened immune system or, in children, Down syndrome
A severe case of nail fungus can be painful and may cause permanent damage to your nails. And it may lead to other serious infections that spread beyond your feet if you have a suppressed immune system due to medication, diabetes or other conditions
These habits can help prevent nail fungus or reinfections:
- Wash your hands and feet regularly and keep your nails short and dry. Wash your hands and feet with soap and water, rinse, and dry thoroughly, including between the toes. Trim nails straight across and file down thickened areas.
- Wear socks that absorb sweat. Fabrics effective at wicking away moisture include wool, nylon and polypropylene. Change your socks often, especially if you have sweaty feet.
- Choose shoes that reduce humidity. It also helps to occasionally take off your shoes or wear open-toe footwear.
- Discard old shoes. If possible, avoid wearing old shoes, which can harbor fungi and cause a reinfection. Or treat them with disinfectants or antifungal powders.
- Use an antifungal spray or powder. Spray or sprinkle your feet and the insides of your shoes.
- Wear rubber gloves. This protects your hands from overexposure to water. Between uses, turn the gloves inside out to dry.
- Don’t trim or pick at the skin around your nails. This may give germs access to your skin and nails.
- Don’t go barefoot in public places. Wear sandals or shoes around pools, showers, and locker rooms.
- Choose a reputable nail salon. Make sure the place you go for a manicure or pedicure sterilizes its instruments. Better yet, bring your own and disinfect them after use.
- Give up nail polish and artificial nails. Although it may be tempting to hide nail fungal infections under a coat of pretty pink polish, this can trap unwanted moisture and worsen the infection.
- Wash your hands after touching an infected nail. Nail fungus can spread from nail to nail.