A hernia is a swelling or lump and is caused by a weakness in the muscles of the abdominal wall. The lump can contain part of the intestines (bowel) or abdominal fatty tissue. They can occur in a variety of places. The commonest is associated with a lump in the groin and is called an inguinal hernia. Other common types include femoral hernia, umbilical hernia and incisional hernia. They may cause no or minimal symptoms. Without treatment hernias can get bigger with time and are at risk of strangulation (having their blood supply cut off). Surgery is often recommended as it is the only way to cure the condition.