An ingrown toenail occurs when the side of the nail curls down and grows into the skin around the nail.

Any toe can be affected but it commonly occurs in the big toe.

An ingrown toenail can become painful and inflamed (tender, red and swollen).

Sometimes, it can become infected, which, if left untreated, can spread and infect the underlying bone.

If you have an ingrown toenail, the area may be:

• painful or tender
• red
• swollen
• surrounded by hardened skin

If the area becomes infected, you may notice fluid or pus, and symptoms that get worse rather than better.

You can get an ingrown toenail if you:

• have tight fitting shoes, socks, or tights that crowd your toes, putting pressure on your toenails
• cut your toenails too short or not straight across
• injure your toe, for example by stubbing it
• pick or tear the corners of your toenails
• have sweaty feet, making your skin soft and easier for toenails to dig in
• have toenails with naturally curved edges or that are fan-shaped

Ingrown toenails become more common in older people as the nails get thicker with age. They are more likely to become infected in people who have diabetes or circulation problems.

If you have diabetes, nerve damage in your leg or foot, poor blood circulation to your foot or an infection around the nail, see your doctor or podiatrist (a trained therapist who diagnoses and treats foot conditions) immediately.

Otherwise, try this:

• Soak your feet in warm water for 15 to 20 minutes, 3 or 4 times a day.
• Then use a cotton bud to gently push away the skin from the nail.
• Repeat each day for a few weeks, allowing the nail to grow.
• As the end of the nail grows forward, push a tiny piece of cotton wool or dental floss under it to help the nail grow over the skin and not grow into it. Change the cotton wool or dental floss each time you soak your foot.
• Do not pick at the toenail or try to remove it yourself.

An infected toenail may be treated with antibiotics. Your doctor or podiatrist may need to drain the pus. In severe cases, part or all of nail may need to be removed.

To help prevent an ingrown toenail:

• wear shoes that fit properly
• keep your feet clean and dry
• trim your nails properly — briefly soak your foot in warm water before trimming, and make sure you cut straight across, without tapering or rounding the corners or cutting them too short

People with diabetes or persistent foot problems should see a podiatrist regularly for routine foot checks and nail care.

Trim your toenails, when needed, after you wash and dry your feet. Using toenail clippers, trim your toenails straight across. Do not cut into the corners of your toenail. Gently smooth each nail with an emery board or nonsharp nail file. Trimming this way helps prevent cutting your skin and keeps the nails from growing into your skin.

Have a foot doctor trim your toenails if

• you cannot see, feel, or reach your feet
• your toenails are thick or yellowed
• your nails curve and grow into the skin

If you want to get a pedicure at a salon, you should bring your own nail tools to prevent getting an infection. You can ask your health care provider what other steps you can take at the salon to prevent infection.