Nexium is a type of medicine known as an acid pump inhibitor (also known as a proton pump inhibitor, or PPI). The lining of your stomach contains millions of special cells that produce acid via "acid pumps." It is the job of these pumps to produce the acid that helps in the digestion of food.

Nexium decreases the amount of acid produced in the stomach. Nexium is used to treat ulcers, gastroesophageal reflux disease (GERD or heartburn), erosive esophagitis, and other conditions involving excessive stomach acid production. Nexium may also be used for purposes other than those listed in this medication guide.