Hernias are abnormal protrusions of abdominal contents through weaknesses or holes in the muscles of the abdominal wall. Patients may notice a bulge or discomfort at the site of the hernia. The commonest sites for a hernia are in the groin (known as an inguinal hernia), at the umbilicus or in an old surgical incision (an incisional hernia). Inguinal hernias occur where the abdominal muscle are weak in the groin since birth. In men the hernia lies adjacent to the blood vessels to the testicles. In women inguinal hernias are less common and lie adjacent to the round ligament. Umbilical hernias bulge through the base of the umbilicus. The muscle is weaker than in surrounding areas as the umbilical cord passed through the muscle at this point. Hernias are common in surgical incisions. The muscle may fail to heal correctly particularly in malnourished, immunosuppressed or obese patients. Patients who develop wound infections or who require chemotherapy after surgery are also at increased risk for incisional hernias.