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: 1/6/2013 Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.