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Why does the acid back up into the esophagus?

A muscle called the lower esophageal sphincter (LES) at the bottom of the esophagus normally prevents foods and acid from backing up. This muscle acts like a tight drawstring to close off the opening between the esophagus and stomach when you are not eating.

Heartburn happens when the lower esophageal sphincter does not close all the way.

Why doesn't the lower esophageal sphincter close all the way?

Many different things loosen the lower esophageal sphincter.

• Certain foods and drinks loosen the lower esophageal sphincter. These include chocolate, peppermint, caffeine-containing beverages (such as coffee, tea, and soft drinks), fatty foods, and alcohol.



• Your body's position affects the lower esophageal sphincter. It is easier for stomach acid to flow back into the esophagus if you are lying down or bending over.



• Anything that increases the pressure on the stomach can force stomach acid backward and cause heartburn. Lifting, straining, coughing, tight clothing, obesity, and pregnancy can worsen heartburn.



• Certain medical conditions increase your chances of having heartburn. Hiatal hernia, diabetes, and many autoimmune diseases (CREST syndrome, Raynaud phenomenon, and scleroderma) are linked to heartburn.



• Many prescription medications can loosen the lower esophageal sphincter, including certain blood pressure and heart medications and the asthma drug theophylline.