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.
Some people learn that their hemoglobin is low when they try to donate blood. Being turned down for blood donation isn't necessarily a cause for concern. You can have a hemoglobin count that's fine for you but doesn't meet the standards blood donation centers set.
If your hemoglobin count is only a little under the required level, particularly if you've been accepted for blood donation in the past, you might just need to wait a couple of months and try again. If the problem continues, make an appointment with your doctor.
Make an appointment if you have signs and symptoms
If you have signs and symptoms of a low hemoglobin count, make an appointment with your doctor. Signs and symptoms can include:
- Fatigue
- Weakness
- Pale skin and gums
- Shortness of breath
- A fast or irregular heartbeat
Your doctor might recommend a complete blood count test to determine whether you have a low hemoglobin count. If your test reveals that you have a low hemoglobin count, you'll likely need more testing to determine the cause.
Show References
- 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.
Original article: https://www.mayoclinic.org/symptoms/low-hemoglobin/basics/definition/sym-20050760