Achlorhydria is a condition in which the stomach does not produce any gastric acid. Often, this has an underlying cause such as a bacterial infection or pernicious anemia, or the presence of risk factors such as diabetes, thyroid disease, or chronic stomach ulcers. People with this condition are at increased risk of malnutrition, infection, and gastric cancer.
Stomach acid is produced by parietal cells, which secrete the acid into the stomach. There are several diseases which can disrupt the process of stomach acid production. In addition, some medications can disrupt this process, including proton pump inhibitors, which are used to treat stomach ulcers, gastroesophageal reflux disease, and similar digestive disorders.
Certain types of gastric surgery also disrupt the production or secretion of stomach acid. One is a gastric bypass procedure called Roux-en-Y, in which the stomach is bypassed with the creation of a small pouch through which food is diverted. Another is called an antrectomy. In this procedure, acid secretion is purposely blocked due to the removal of a portion of the stomach. Antrectomy is a treatment for certain cancers and digestive disorders.
Infection with Helicobacter pylori can disrupt the production of stomach acid and cause achlorhydria. This bacterial species causes stomach ulcers, and produces substances that interfere with stomach acid secretion to promote its own survival. Some medical conditions also cause achlorhydria. One of these is pernicious anemia, caused by vitamin B12 deficiency. A rare genetically-inherited disorder called mucolipidosis type IV can disrupt stomach acid production due to abnormally high levels of fat or carbohydrate storage in parietal cells.
One of the most common gastric achlorhydria symptoms is malnutrition, which is caused by a decreased ability to absorb vitamins and minerals. The stomach also has a reduced ability to digest protein. Impaired digestion typically causes stomach pain, as the stomach is trying to digest food without the aid of gastric acid. Symptoms similar to those of gastroesophageal reflux disease are common; these include heartburn, nausea, trouble swallowing, and regurgitation of food.
Treatment of achlorhydria depends on the underlying disease which is disrupting production or secretion of stomach acid. In the case of chronic stomach ulcers caused by Helicobacter pylori infection, for example, the main objective is to treat the infection with antibiotics. Pernicious anemia may be treated with vitamin B12 supplements. Patients are also screened for other vitamin deficiencies that may need to be corrected. When the cause is long-term treatment with proton pump inhibitors, the dose may be reduced to try and correct the stomach acid problem.