When the fingernail starts growing in the skin, the problem is known as ingrown fingernail. The nail becomes curved and is embedded in the skin around the nail. The area around the affected nail becomes red and swollen. This painful condition causes a lot of discomfort. The problem usually occurs in nails of toes. The condition is caused by trimming and cutting the nail in a wrong way. It can also be due to wearing poorly fitted shoes. Nail injury is another cause of this problem. It is important to treat ingrown fingernails otherwise there is a high risk of infection. Infection can cause pus formation. Following are some tips on how to treat an ingrown fingernail.