Changes in body position may exacerbate heartburn. Heartburn can be associated with gastrointestinal reflux. When the patient is standing, abdominal pressure is low and stomach contents are less affected by body position. When the patient lies down, the abdominal pressure is raised and the stomach contents tend to reflux, causing discomfort such as a feeling of heartburn. Therefore, people with heartburn should visit a gastroenterologist promptly. In addition, take care not to lie down too early after meals, and sleep with your upper body elevated.