Ingrown nails (unguis incarnatus), is a common form of nail disease. Onychocryptosis also known as Ingrown nails. Ingrown nails may develop for many reasons. Some cases are congenital--the nail is just too large for the toe. Trauma, such as stubbing the toe or having the toe stepped on, may also cause an ingrown nail. However, the most common cause is tight shoe wear or improper grooming and trimming of the nail. The ingrown nail can also apply pressure in the nail fold area without penetrating the skin - this is not technically an ingrown toe nail, but can also be painful (a corn/callus is also common down the side of the nail and is a reaction to this pressure, rather than the nail actually penetrating the skin). Poor maintenance, like cutting the nail too short, rounded off at the tip or peeled off at the edges (versus being cut straight across), is likely to cause ingrowth. Some In growing toe nails are acute which means that they have occurred due to a injury to the toe. Others are chronic, which means the patient has had the problem for a long period of time. The large toe is usually affected, however, it can also affect the lesser toes.

Symptoms of an ingrown nail include pain along the margins of the nail (caused by hypergranulation that occurs around the aforementioned region). Some ingrown toenails are chronic, with repeated episodes of pain and infection. Irritation, redness, an uncomfortable sensation of warmth, as well as swelling can result from an ingrown toenail. Bumping of an affected toe with objects can produce sharp, even excruciating, pain as the tissue is punctured further by the ingrown nail. By the very nature of the condition, ingrown nails become easily infected unless special care is taken to treat the condition early on and keep the area as clean as possible. Signs of infection include redness and swelling of the area around the nail, drainage of pus and watery discharge tinged with blood. The main symptom is swelling at the base of the nail on whichever side (if not both sides) the ingrowing nail is forming. The infection can spread, making the toe red and inflamed (paronychia). A collection of pus may also develop.

Ingrown toenails should be treated as soon as they are recognized. Treatment of ingrown nails ranges from soaking the afflicted area to surgery. Sometimes antibiotics are used to help the infection clear after the nail has been removed. Peroxide is immediately effective to help clean minor infections but iodine is more effective in the long term as it continues to prevent bacterial growth even after it is dry. The problem is congenital, the best way to prevent ingrown toenails is to protect the feet from trauma and wear shoes with adequate room for the toes. Soak the foot in warm water 3-4 times daily. Bandages can help keep out bacteria but one should never apply any of the new types of spray-on bandages to ingrown nails that show any discharge - preventing drainage will likely cause intense swelling and pain. Cutting toe nails properly goes a long way toward the prevention of ingrown toenails. Using a safety nail clipper, cut the nails straight across, so that the nail corner is visible. Trim nails straight across. Don't pick at your nails or tear them at the corners. If the nail is not deeply ingrown, the edge of the nail can be lifted from the skin edge that it is irritating. A small piece of clean cotton can then be used to prop the nail's corner up and over the skin edge until the skin heals.