why am i having heartburn

Heartburn happens because stomach acid backs up into the esophagus, causing a burning sensation in the chest or throat. This often occurs when the lower esophageal sphincter (LES), a valve between the esophagus and stomach, doesn't close properly or becomes weakened. Common causes include eating acidic, fatty, or spicy foods, large meals, certain medications (like aspirin or ibuprofen), smoking, being overweight, pregnancy, and conditions like hiatal hernia. Other triggers include lying down after eating, stress, and tight- fitting clothing. The acid reflux irritates the esophagus, leading to the uncomfortable burning feeling known as heartburn.