An ingrown toenail, also known as onychocryptosis or unguis incarnates, is a painful condition of the toe. It occurs when a sharp corner of the toenail digs into the skin at the end of or side of the toe. Pain and inflammation at the spot where the nail curls into the skin occurs first. Later, the inflamed area can begin to grow extra tissue or drain yellowish fluid.

* If left untreated, an ingrown toenail can progress to an infection or even an abscess that requires surgical treatment. Osteomyelitis is a rare complication of an infected toe, in which the bone itself becomes infected.

* Ingrown toenails are common in adults but uncommon in children and infants. They are more common in men than in women. Young adults in their 20s or 30s are most at risk.

* Any toenail can become ingrown, but the condition is usually found in the big toe.
* Tight-fitting shoes or high heels cause the toes to be compressed together and pressure the nail to grow abnormally.

* Improper trimming of toenails can cause the corners of the nail to dig into the skin. Nails should be trimmed straight across, not rounded.

* Disorders such as fungal infections of the nail can cause a thickened or widened toenail to develop.

* Either an acute injury near the nail or anything that causes the nail to be damaged repetitively (such as playing soccer) can also cause an ingrown nail.

* If a member of your family has an ingrown toenail, then you are more likely to develop one, too. Some people’s nails are normally more rounded than others, which increases the chance of developing ingrown nails.