What is a hernia? A hernia is a condition in which an organ or other structure protrudes through a weak part of tissue or muscle. In some cases, a hernia can create a visible lump or bulge in the skin. Many people do not understand what a hernia is. Hernias are classified according to the site of protrusion: Congenital diaphragmatic hernia is a birth defect that allows abdominal organs to protrude up into the chest cavity. Femoral hernia is the protrusion of abdominal fat or part of the intestines through the abdominal muscles into the upper thigh area. Hiatal hernia is the protrusion of a portion of the stomach through an opening in the diaphragm called the hiatus. Hiatal hernia is also called a hiatus hernia. Incisional hernia is a hernia that develops through a surgical incision. Inguinal hernia is the protrusion of abdominal fat or part of the intestines through the abdominal muscles into the groin area (also called the inguinal canal). Inguinal hernia is the most common type of hernia. Umbilical hernia is the protrusion of part of the intestines or abdominal lining through the abdominal wall around the belly button. It most often occurs in infants ages six months and younger. In some cases, a hernia may not cause any symptoms and treatment is not necessary. However, a hernia can be uncomfortable, painful, or even a medical emergency in some cases. Hernias are often readily treated through lifestyle changes, medication, and surgery. Complications of a hernia can be serious and include incarcerated hernia and strangulated hernia. Seek prompt medical care if you suspect that you, or your infant, have a hernia. Early diagnosis and treatment can minimize discomfort and the risk of complications. Seek immediate medical care (call 911) if you, or someone you are with, have difficulty breathing or severe abdominal pain, or if your hernia becomes discolored or does not go back in place by itself or with gentle pressure.