Hyperpepsinia is the presence of excessive pepsin — or excessive peptic activity — in the gastric juice: the stomach’s protein-digesting enzyme running hotter than normal. Since pepsin is activated by acid and does its damage wherever the mucosal barrier is breached, hyperpepsinia partners hyperchlorhydria in attacking the stomach and duodenal lining — the twin excesses behind peptic ulcer formation. Zollinger-Ellison syndrome’s gastrin floods drive both. The term belongs to the precise vocabulary of gastric physiology, distinguishing enzyme excess from acid excess, though clinically the two usually travel together and treatment — acid suppression — quells both. It is a reminder that digestion’s tools are corrosive by design.