Chronic GERD that is untreated can cause serious complications. Inflammation of the esophagus from refluxed stomach acid can damage the lining and cause bleeding or ulcers—also called esophagitis. Scars from tissue damage can lead to narrowing of the esophagus that make swallowing difficult. Some people develop a disease, in which parts of the esophageal lining take on an abnormal shape and color. Over time, the cells can lead to esophageal cancer. Persons with GERD and its complications should be monitored closely by a doctor.

Studies have shown that GERD may worsen or contribute to asthma, chronic cough, and pulmonary fibrosis.