Understanding Heartburn -- the Basics

What Is Heartburn?

Despite its name, heartburn has nothing to do with the heart. Some of the symptoms, however, are similar to those of a heart attack or heart disease.

Heartburn is an irritation of the esophagus that is caused by stomach acid. This can create a burning discomfort in the upper abdomen or below the breast bone.

With gravity's help, a muscular valve called the lower esophageal sphincter, or LES, keeps stomach acid in the stomach. The LES is located where the esophagus meets the stomach -- below the rib cage and slightly left of center. Normally it opens to allow food into the stomach or to permit belching, then closes again. But if the LES opens too often or does not close tight enough, stomach acid can reflux, or seep, into the esophagus and cause the burning sensation.

Occasional heartburn isn't dangerous, but chronic heartburn or gastroesophageal reflux disease (GERD) can sometimes lead to serious problems.

Heartburn is a weekly occurrence for up to 20% of Americans and is very common in pregnant women.

What Causes Heartburn?

The basic cause of heartburn is a lower esophageal sphincter, or LES, that doesn't tighten as it should. Two excesses often contribute to this problem: too much food in the stomach (overeating) or too much pressure on the stomach (frequently from obesity, pregnancy, or constipation). Certain foods commonly relax the LES, including tomatoes, citrus fruits, garlic, onions, chocolate, coffee, alcohol, caffeinated products, and peppermint. Meals high in fats and oils (animal or vegetable) often lead to heartburn, as do certain medications. Stress and lack of sleep can increase acid production and can cause heartburn. And smoking, which relaxes the LES and stimulates stomach acid, is a major contributor.

WebMD Medical Reference Reviewed by Melinda Ratini, DO, MS on March 18, 2015

Sources

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DeVault, K. and Castell, D. American Journal of Gastroenterology, 2005. 

Pettit, M. Pharmacy World and Science, December 2005. 

Talley, N. and Vakil, N. American Journal of Gastroenterology, October 2005.

Feldman, M. Sleisenger and Fordtran's Gastrointestinal and Liver Disease, 9th ed., Saunders, 2010.

National Digestive Diseases Information Clearing House: "Digestive Diseases Statistics for the United States."

Gabbe, S. Obstetrics: Normal and Problem Pregnancies 5th ed., Churchill Livingstone, 2007.

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