Summary: Indigestion, also known as dyspepsia, is a condition of impaired digestion. Symptoms may include upper abdominal fullness, heartburn, nausea, belching, or upper abdominal pain. People may also experience feeling full earlier than expected when eating. Dyspepsia is a common problem and is frequently caused by gastroesophageal reflux disease (GERD) or gastritis. In a small minority of cases it may be the first symptom of peptic ulcer disease (an ulcer of the stomach or duodenum) and, occasionally, cancer. Hence, unexplained newly onset dyspepsia in people over 55 or the presence of other alarming symptoms may require further investigations.
Reference Material:
https://en.wikipedia.org/wiki/Functional_dyspepsia
