A hiatal hernia occurs when part of the stomach protrudes up into the chest through the sheet of muscle called the diaphragm. This may result from a weakening of the surrounding tissues and may be aggravated by obesity and/or smoking.
Review Date: 5/2/2023
Reviewed By: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.