A hiatal hernia occurs when a part of the stomach pushes through the diaphragm, the muscle that separates the chest from the abdomen. This can happen due to increased pressure in the abdomen, often caused by factors like obesity, pregnancy, or heavy lifting. Symptoms may include heartburn, regurgitation, and difficulty swallowing. While many people with a hiatal hernia experience no symptoms, treatment options are available for those who do, including lifestyle changes, medications, or surgery in severe cases.