Life Science Encyclopedia

Achlorhydria and hypochlorhydria refer to states where gastric acid levels are either absent or low in the stomach.

Causes

• Autoimmune disorders where there is antibody production against parietal cells which normally produce gastric acid.

• The use of antacids or drugs that decrease gastric acid production (such as H2-receptor antagonists) or transport (such as proton pump inhibitors).

• A symptom of rare diseases such as mucolipidosis (type IV).

• A symptom of Helicobacter pylori infection which neutralizes and decreases secretion of gastric acid to aid its survival in the stomach.

• A symptom of pernicious anemia, atrophic gastritis, VIPomas or of stomach cancer.

Diagnosis

90% of all patients with achlorhydria have detectable antibodies against the H+/K+ ATP-ase proton pump. The diagnosis is made if the gastric pH remains high (>4.0) despite maximum pentagastrin stimulation. High gastrin levels are often detected.

Presentation

Achlorhydria and hypochlorhydria may lead to microbial overgrowth since the disinfectant qualities of gastric acid are diminished. This can increase the risk of infections in the digestive tract (such as Vibrio or Helicobacter infections).

Treatment

Treatment focuses on addressing the underlying cause, injection of vitamins like vitamin B12 (which is poorly absorbed in the absence of intrinsic factor) in autoimmune disorders, and avoiding foods that may have a high microbial load.

See also

• Hyperchlorhydria