Achylia refers to a medical condition where the stomach fails to produce enough hydrochloric acid, which is necessary for the digestion of food. Synonyms for achylia include hypoacidia, hypochlorhydria, and achlorhydria. All these terms refer to the same condition and are interchangeable. Hypoacidia is a mild reduction in the stomach's acid production, while hypochlorhydria is a moderate drop in acid secretion. On the other hand, achlorhydria is a complete absence of hydrochloric acid in the stomach. Regardless of the degree of acid reduction, achylia can cause notable digestive problems, including indigestion, bloating, and malabsorption of nutrients.