Heartburn is a burning pain in the chest, just behind the breastbone, that is caused by stomach acid backing up into the esophagus. The most common cause of heartburn is when the lower esophageal sphincter (LES), a muscular valve that separates the esophagus from the stomach, relaxes and allows stomach acid to flow back up into the esophagus. Other causes of heartburn include:

• Foods: Certain foods can trigger heartburn, such as those that are acidic or high in fat, including citrus fruits, tomatoes, onions, chocolate, coffee, cheese, and peppermint.

• Large meals: Eating large meals can cause heartburn because they put pressure on the LES and cause stomach acid to flow back up into the esophagus.

• Medications: Certain medications, such as aspirin or ibuprofen, as well as some sedatives and blood pressure medications, can cause heartburn.

• Smoking: Tobacco in cigarettes can affect LES function and cause heartburn.

• Being overweight or pregnant: Added pressure on the abdomen and stomach from being overweight or pregnant can trigger heartburn.

Symptoms of heartburn include a burning pain in the chest that usually occurs after eating and may occur at night, pain that worsens when lying down or bending over, a sour taste in the mouth, coughing, or hoarseness. Heartburn that occurs frequently and interferes with daily routine is considered gastroesophageal reflux disease (GERD) and may require prescription medications and, occasionally, surgery or other procedures.