A hiatal hernia occurs when a portion of the stomach pushes upward through the diaphragm into the chest cavity. The diaphragm is a muscle that separates the chest from the abdomen, and the opening in the diaphragm (called the hiatus) normally allows the esophagus to pass through. In the case of a hiatal hernia, the stomach bulges through this opening, which can lead to gastroesophageal reflux disease (GERD), heartburn, chest pain, and difficulty swallowing. There are two main types: sliding hernias, where the stomach and part of the esophagus move above the diaphragm, and paraoesophageal hernias, where part of the stomach pushes through but the esophagus remains in place. Many people with a hiatal hernia experience mild symptoms or none at all, while others may have more severe discomfort. Treatment often involves lifestyle changes, medications to reduce stomach acid, and in some cases, surgery to repair the hernia. For most patients, managing symptoms helps to improve quality of life and prevent complications.