The Basics of Heartburn and Acid Reflux

Medically Reviewed by Carol DerSarkissian, MD on March 16, 2023
3 min read

Despite its name, heartburn has nothing to do with the heart (although some of the symptoms are similar to a heart attack). Heartburn, also called acid indigestion, is an irritation of the esophagus caused by acid that refluxes (comes back up) from the stomach.

When swallowing, food passes down the throat and through the esophagus to the stomach. Normally, a muscular valve called the lower esophageal sphincter (LES) opens to allow food into the stomach (or to permit belching); then it closes again. Next, the stomach releases strong acids to help break down the food. But if the lower esophageal sphincter opens too often or does not close tight enough, stomach acid can reflux, or seep back into the esophagus, causing the burning sensation we know as heartburn.

Not only can stomach acid in the esophagus cause heartburn, but it sometimes causes damage to the esophagus in the form of esophagitis, ulcers, difficulty or pain when swallowing, strictures (narrowing), esophageal spasm, and Barrett's esophagus which may increase the chance of cancer of the esophagus.

Most people have felt heartburn at one time or another. In fact, the American Gastroenterological Association reports that more than 60 million Americans experience heartburn/reflux symptoms at least once each month. Though uncomfortable, heartburn does not usually present a serious health problem for most people.

However, if heartburn symptoms occur frequently and persistently, they can be an indicator of a more serious problem, such as gastroesophageal reflux disease, or GERD. Left untreated, GERD can cause a host of complications, including cancer.

Gastroesophageal reflux disease is a relatively common condition that affects from up to 20% of the population. It is a chronic reflux of stomach acid into the esophagus. GERD manifests itself as several symptoms including heartburn, regurgitation, and difficulty swallowing. Thus, if heartburn symptoms occur frequently and persistently, they are most likely caused by GERD.

The severity of GERD depends on lower esophageal sphincter dysfunction, as well as the type and amount of fluid brought up from the stomach.

Treatments aim to reduce the amount of reflux or reduce the potential for damage to the esophageal lining from refluxed substances.

In addition, doctors recommend lifestyle and dietary modification to lessen acid reflux.

Various lifestyle and dietary factors can contribute to heartburn by relaxing the lower esophageal sphincter and allowing it to open, increasing the amount of acid in the stomach, increasing stomach pressure, or by making the esophagus more sensitive to harsh acids. These factors include:

Dietary Habits

  • Eating large portions
  • Eating certain foods, including onions, chocolate, peppermint, high-fat or spicy foods, citrus fruits, garlic, and tomatoes or tomato-based products
  • Drinking certain beverages, including citrus juices, alcohol, and caffeinated and carbonated drinks
  • Eating before bedtime

Lifestyle Habits

  • Being overweight
  • Smoking
  • Wearing tight-fitting clothing or belts
  • Lying down or bending over, especially after eating

Medical Causes