Nail Infections

Nail infections (also known as fungal nail infections) are common infections of the fingernails or toenails. These infections can cause the nail to become discolored and more likely to crack or break. In most cases, a fungal nail infection is not painful. If the infection becomes severe, then you may notice pain. Nail infections are more common in toenails than fingernails.

Anyone can get a fungal nail infection at any age. Some people may be more likely to get nail infections than others, including people who have the following conditions:

• Injury to the nail
• Surgery on a fingernail or toenail
• Diabetes
• Weakened immune system
• Reduced blood circulation to the feet or hands
• Athlete’s foot

A severe case of a nail infection may cause permanent damage to your nails. The infection may also spread to other parts of the body. 

Common symptoms of a fungal nail infection include the following:

• Discolored fingernail or toenail (nail may turn yellow, brown, or white)
• Nail becomes thick
• Nail begins to crack or break
• Nail appears distorted in shape

Nail infections will usually go away without treatment. Contact your healthcare provider if your symptoms are getting worse, or if you are experiencing pain.

Nail infections are caused by an overgrowth of fungi. Fungi are a natural and common part of the environment. While most aren’t harmful to the body, some can cause health problems, especially for people with weakened immune systems. Fungi are also more likely to grow in places that are warm and damp, such as in a closed shoe.

Your doctor can often diagnose fungal nail infections during a physical examination. He or she may take some nail clippings or skin samples from under your nail that will be sent the lab to identify the type of fungus causing the infection.

Nail infections will usually go away without treatment. Your doctor may also recommend over-the-counter medicines. If your body is not responding to the over-the-counter medicines, or if your symptoms are getting worse, your doctor may recommend the following treatments:

• Oral antifungal medicines
• Medicated nail polish
• Medicated nail cream
• Surgical removal of the nail (in severe cases)

Fungal nail infections may take weeks or even months to resolve. Even after the infection is treated, repeat nail infections may occur.

There are steps you can take to prevent nail infections, including:

• Washing your hands regularly
• Keeping your hands and feet clean and dry
• Clipping your fingernails and toenails regularly
• Avoiding walking barefoot in public areas, such as locker rooms
• Wearing shoes that fit appropriately 

US National Library of Medicine

American Academy of Dermatology

Nail infections (also known as fungal nail infections) are common infections of the fingernails or toenails. These infections can cause the nail to become discolored and more likely to crack or break. Different types of fungi, including dermatophytes [der-mat-ah-fites], yeasts, and molds cause nail infections.