A hernia (rupture) usually appears as a lump, commonly in the groin or in the umbilical region. It is developed when a portion of the tissue lining the abdominal cavity (peritoneum) breaks through a weakened area of the abdominal wall. This can give rise to discomfort as the hernia enlarges and can sometimes be dangerous, if a piece of intestine becomes trapped ('strangulated') inside.
There are various kinds of hernia affecting the various parts of the body and they are named according to the position of its development.
Hiatus hernia is a condition when the upper part of the stomach, which is joined to the esophagus (gullet), moves up into the chest through the hole (called a hiatus) in the diaphragm. This can result in painful burning sensation unlike the other hernias which often appear without symptoms. It is common and occurs in about 10 per cent of people.
The diaphragm is a sheet of muscle that separates the lungs from the abdomen. When a person takes a deep breath, the dome-shaped diaphragm contracts and flattens. In doing this, the diaphragm pulls air into the lungs. The left diaphragm contains a small hole through which passes the tube-shaped esophagus that carries food and liquid to the stomach. Normally this hole, called a hiatus, is small and fits snugly around the esophagus. The J-shaped stomach sits below the diaphragm.