Acid reflux occurs when stomach acid flows back into the esophagus, causing a burning sensation known as heartburn. It is often triggered by certain foods and drinks, such as spicy foods, caffeine, alcohol, and fatty meals. Other causes include obesity, smoking, and lying down soon after eating. Chronic acid reflux can lead to gastroesophageal reflux disease (GERD/GORD), which requires medical attention. Lifestyle changes, antacids, and medications can help manage symptoms and prevent complications.