What is heartburn?

Heartburn is a burning sensation in the upper abdomen or breastbone that results from irritation of the esophagus, according to WebMD. The cause of the irritation is stomach acid. The name "heartburn" stems from the symptoms, which are similar to those of a heart attack, though the heart isn't affected.

A person experiences heartburn when the lower esophageal sphincter, or LES, closes too often or not often. This situation allows stomach acid to reflux or seep into the esophagus. About 20 percent of Americans experience weekly heartburn, and pregnant women are especially susceptible, reports WebMd. Occasional heartburn isn't uncommon. Chronic heartburn, known as gastroesophageal reflux disease, can cause more significant health problems.