A low hemoglobin count is a commonly seen blood test result. Hemoglobin (Hb or Hgb) is a protein in red blood cells that carries oxygen throughout the body.
A low hemoglobin count is generally defined as less than 13.2 grams of hemoglobin per deciliter (132 grams per liter) of blood for men and less than 11.6 grams per deciliter (116 grams per liter) for women. In children, the definition varies with age and sex. These thresholds may differ slightly from one medical practice to another.
In many cases, a low hemoglobin count that's only slightly lower than normal doesn't affect how you feel. A low hemoglobin count that's more severe and causes symptoms might mean you have anemia.
May 24, 2022
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- Hemoglobin. Lab Tests Online. https://labtestsonline.org/tests/hemoglobin. Accessed March 6, 2020.
- McPherson RA, et al. Erythrocytic disorders. In: Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. Elsevier Inc.; 2017. https://www.clinicalkey.com. Accessed March 6, 2020.
- Leung LLK. Approach to the adult with anemia. https://www.uptodate.com/contents/search. Accessed March 6, 2020.
- Low red blood cell counts (anemia). American Cancer Society. https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/low-blood-counts/anemia.html. Accessed March 6, 2020.
- Donors deferred for low hemoglobin. American Red Cross. https://www.redcrossblood.org/donate-blood/blood-donation-process/before-during-after/iron-blood-donation/donors-deferred-forlowhemoglobin.html. Accessed March 20, 2020.