Hemoglobin Test
Reviewed
A hemoglobin test measures the level of hemoglobin in your blood. Hemoglobin is an iron-rich protein in red blood cells that carries oxygen from your lungs to the rest of your body. The test is often used to check for anemia and is usually part of a complete blood count (CBC).
Preparation and collection
No special preparation is needed. If your provider has ordered other blood tests, you may need to fast for several hours beforehand.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- The test cannot tell you what is causing an abnormal level.
- Abnormal results do not always mean you have a medical condition that needs treatment.
- Results can be affected by diet, activity level, medications, dehydration, smoking, certain genetic conditions, and living at a high altitude.
What to do next
Talk with your provider about your results. Your provider will consider your symptoms, medical history, and other blood test results to understand your hemoglobin levels.