Indigestion - also called dyspepsia or an upset stomach - is a general term that describes discomfort in your upper abdomen. Indigestion is not a disease, but rather some symptoms you experience, including abdominal pain and a feeling of fullness soon after you start eating. Although indigestion is common, each person may experience indigestion in a slightly different way. Symptoms of indigestion may be felt occasionally or as often as daily.Indigestion can be a symptom of another digestive disease. Indigestion that isn't caused by an underlying disease may be eased with lifestyle changes and medication