What causes hiatus hernia and how common is it?
Hiatus hernias are common. It is estimated that up to half of people develop a hiatus hernia, usually in middle age. Many are small, and many people with a hiatus hernia do not know they have it as it often causes no symptoms. The cause of hiatus hernia is not clear. Most cases occur in people over the age of 50. It may be that the diaphragm weakens with age and allows part of the stomach to protrude through the hole in the diaphragm. Factors which increase the pressure in the abdomen such as regular coughing or obesity may increase the risk of developing a hiatus hernia. (There is a rare type of hiatus hernia which occurs in newborn babies due to a congenital defect of the stomach or diaphragm.
