Dyspepsia refers to a condition (disease) in which there are upper abdominal symptoms which may include upper abdominal pain, bloating (a feeling of abdominal fullness without objective abdominal distention), early satiety (a feeling of unusual fullness with very little intake of food), nausea, or belching. The symptoms often are provoked by eating.
Dyspepsia is considered a functional disease. (Another functional disease is irritable bowel syndrome or IBS.) Functional diseases are diseases in which no abnormalities can be seen anatomically, for example, on x-rays, or histologically under the microscope. The abnormalities are believed to be due to altered function, primarily of the muscles and nerves of the gastrointestinal tract.
Attempts have been made to subcategorize dyspepsia into ulcer-like, dysmotility-like, reflux-like, and unspecified; however, the utility of this categorization is unclear.
A French writer (1862) called dyspepsia "the remorse of a guilty stomach." The word "dyspepsia" came into English usage in 1706. It was contrived by cementing "dys-" to the Greek "pepsis" (digestion) = dysdigestion = indigestion. Contrary to the implication of this derivation, there is little evidence that digestion is affected in dyspepsia.