Millions of people every year feel the burn – heartburn, that is. Occasional, mild heartburn can have many causes, including eating a large meal, eating fried or spicy foods, or laying down too soon after eating. But when you get heartburn frequently, or symptoms are severe, it may be something more. Acid reflux and gastroesophageal reflux disease (also known as GERD) are medical conditions that can cause long-term health problems and may require medication and treatment.