Possible causes of a hiatal hernia include injury, being born with a large hiatus, and pressure on the muscles surrounding the hiatus, according to Mayo Clinic. This pressure can result from repetitive vomiting, lifting heavy items or coughing. Pregnancy and obesity also cause pressure in this area, reports WebMD. Smoking increases a person's risk of developing a hiatal hernia, states Healthline.
Many hiatal hernias have no known cause, explains Healthline. They occur when the muscle tissue that surrounds the hiatus becomes weak, allowing the stomach to protrude through the diaphragm. Age-related changes in the diaphragm make individuals 50 and older more likely to develop hiatal hernias than younger people, states Mayo Clinic. Certain abdominal exercises and wearing tight belts may make the condition worse. Individuals who strain during bowel movements frequently also increase pressure in the area and should try to avoid this straining.
A hiatal hernia is also more likely to develop in individuals who have ascites, which is an unnatural collection of fluid in the abdomen, reports MedicineNet. Physicians recommend that patients who have hiatal hernias maintain a healthy weight and refrain from lifting heavy items without assistance, states Healthline. Patients should also avoid straining their abdominal muscles in general.