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Achlorhydria Differential Diagnoses

  • Author: Divyanshoo Rai Kohli, MD; Chief Editor: BS Anand, MD  more...
Updated: Jul 15, 2016

Diagnostic ConsiderationsImportant considerations

Long-term proton pump inhibitor (PPI) therapy has been associated with two major complications. As described previously, there is an association with hip fractures in patients with achlorhydria on PPI therapy. In addition, current use of gastric acid suppressive therapy has been associated with an increased risk of community-acquired pneumonia (CAP).

Sustained achlorhydria has been observed after PPI treatment in a patient with Zollinger-Ellison syndrome (ZES), starting soon after treatment began and becoming complete within 6 months.

Gastric resection, leading to surgically induced achlorhydria, has been associated with severe postoperative infections. It has been observed in humans that the lack of an acidic environment may favor bacterial overgrowth. This, in turn, can lead to various nutrient deficiencies with significant clinical manifestation.

According to a study from the Netherlands by Janssen et al, patients with achlorhydria who take nonsteroidal anti-inflammatory drugs (NSAIDs) develop upper gastrointestinal ulcers during NSAID use in a similar fashion as patients who produce acid normally.[17]

Drug-induced achlorhydria is a particularly important condition in elderly patients, in whom it may be associated with secondary bacterial overgrowth.

Patients with pernicious anemia and achlorhydria may demonstrate impaired absorption of iron and may be screened for iron deficiency.

Differential Diagnoses

Contributor Information and Disclosures

Divyanshoo Rai Kohli, MD Fellow, Department of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine

Divyanshoo Rai Kohli, MD is a member of the following medical societies: American College of Physicians

Disclosure: Nothing to disclose.


Timothy R Koch, MD Professor of Medicine (Gastroenterology), Georgetown University School of Medicine

Timothy R Koch, MD is a member of the following medical societies: American College of Gastroenterology, American Gastroenterological Association, American Physiological Society

Disclosure: Nothing to disclose.

Jennifer (Zone-En) Lee, MD Fellow, Section of Gastroenterology, Georgetown University School of Medicine, Washington Hospital Center

Jennifer (Zone-En) Lee, MD is a member of the following medical societies: American College of Gastroenterology, American Gastroenterological Association, American Society for Gastrointestinal Endoscopy

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

BS Anand, MD Professor, Department of Internal Medicine, Division of Gastroenterology, Baylor College of Medicine

BS Anand, MD is a member of the following medical societies: American Association for the Study of Liver Diseases, American College of Gastroenterology, American Gastroenterological Association, American Society for Gastrointestinal Endoscopy

Disclosure: Nothing to disclose.

Additional Contributors

David Greenwald, MD Professor of Clinical Medicine, Fellowship Program Director, Department of Medicine, Division of Gastroenterology, Montefiore Medical Center, Albert Einstein College of Medicine

David Greenwald, MD is a member of the following medical societies: Alpha Omega Alpha, New York Society for Gastrointestinal Endoscopy, American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, American Society for Gastrointestinal Endoscopy

Disclosure: Nothing to disclose.


Hiral Shah, MD Chief Resident, Department of Internal Medicine, Georgetown University Hospital at Washington Hospital Center

Hiral Shah, MD is a member of the following medical societies: American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, and American Medical Association

Disclosure: Nothing to disclose.

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