Achlorhydria: A lack of hydrochloric acid in the digestive juices in the stomach (in technical terms, so that the pH of the stomach contents fails to fall below 4.0 under maximal stimulation). Hydrochloric acid helps digest food.

Achlorhydria can be due to many diverse causes including: Pernicious anemia -- an autoimmune gastritis. Other autoimmune conditions -- such as autoimmune thyroid disease. Any cause of severe chronic gastritis -- H. pylori is the most common agent that may lead to destruction of parietal cells (the cells that make the hydrochloric acid) in the stomach, resulting in achlorhydria. Mucolipidosis type IV -- an autosomal recessive lysosomal storage disease.

The word "achlorhydria" comes from the Greek "a-" (without) + "chlorhydric" (acid) = without acid.