Heartburn, also known as acid reflux, occurs when stomach acids and fluids move up into the esophagus, causing a burning sensation in the chest and throat. It is often caused by eating large meals, fried foods, carbonated drinks, smoking, being overweight, pregnancy, or laying down after eating. Common foods that trigger heartburn include French fries, chips, cheeses, whole milk, spicy foods, raw onions, sodas, alcohol, and coffee. Heartburn can be treated at home by eating smaller meals, avoiding eating close to bedtime, losing weight, and avoiding trigger foods.