Final answer:
Indigestion is a condition of impaired digestion and can present with symptoms such as upper abdominal fullness or pain, heartburn, nausea, and belching. It can be a symptom of organic diseases such as GERD, gastritis, or peptic ulcer, but very rarely, it may be a sign of cancer.
Step-by-step explanation:
Indigestion, or dyspepsia, is a condition of impaired digestion that can present with symptoms such as upper abdominal fullness or pain, heartburn, nausea, belching, or a combination of these symptoms. While the majority of cases occur without evidence of an organic disease, indigestion can also be a symptom of an organic disease such as gastroesophageal reflux disease (GERD), gastritis, or peptic ulcer. In very rare cases, indigestion may be a sign of cancer.