What is the definition or description of: hernia?

A "hole in the wall": A hernia is a hole in the abdominal wall thru which the inner lining protrudes thru, creating a sac. Organs from within the abdominal cavity, such as the intestine, can protrude thru the hole and get stuck in the sac. Many hernias develop during fetal life and become evident in childhood or as an adult. Some develop following a prior abdominal operation. The cornerstone of rx is surgery.

Hole: A hole in the abdominal musculature may allow passage of abdominal organs, usually fat and/or intestines. Similar to a hole in a car tire with the inner tube bulging out. This occurs commonly in the groin (inguinal hernia), the belly button (umbilical hernia) and the diaphragm (hiatal hernia). The lump seen is the result of the hernia, but no lump is seen with a hiatal hernia.