Hemoglobin

Also known as: Hgb; Hb

Formal name: Hemoglobin

The Test Sample

What is being tested?

This test measures the amount of hemoglobin, a protein found in red blood cells, in a blood sample, which is a good indication of the blood’s ability to deliver oxygen to tissues and organs and to transport the waste product carbon dioxide to the lungs, where it is exhaled. If your hemoglobin levels are low, you may have anemia, a condition in which your body is not getting enough oxygen, causing fatigue and weakness.

The hemoglobin rises when the number of red blood cells increases. The hemoglobin falls to less than normal, indicating anemia, when your body decreases its production of red blood cells, increases its destruction of red blood cells, or if blood is lost due to bleeding.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in your arm or by a fingerstick (for children and adults) or heelstick (for newborns).

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.