Hemoglobin - The Oxygen-Carrying Protein in Red Blood Cells
A hemoglobin test measures how much of the oxygen-carrying protein is in your blood, almost always run as part of a complete blood count.
A hemoglobin test measures how much of the oxygen-carrying protein hemoglobin is in your blood, and it is almost always run as part of a complete blood count. A low result may mean iron deficiency; a high result can come from factors such as smoking or altitude and needs clinical interpretation.
The biomarker
- Name: Hemoglobin
- Units: g/dL
- Standard reference range: about 13.8 to 17.2 g/dL for adult men and 12.1 to 15.1 g/dL for adult women (ranges vary by lab)
How to read your result
| Value | Interpretation |
|---|---|
| Below your lab's range | Needs clinical interpretation, usually alongside the rest of the blood count and a repeat test |
| Within your lab's range | Within the laboratory range printed on your own report — ranges differ by sex, age and lab, so compare your value with your own report's range |
| Above your lab's range | Needs clinical interpretation, including factors such as smoking and altitude |
What moves the needle
- Never. Do not start or stop any supplement or medicine on the strength of one value — ask your clinician first.
- If flagged. Ask whether the test should be repeated and which related tests belong with it.
- Before the test. No special preparation is needed for a hemoglobin test; it is usually part of a complete blood count.
- Tell the clinician. Mention every medicine and supplement you take, and whether you smoke or live at high altitude.
Why this test is worth asking for
- It is the protein that carries oxygen around the body, so it is a direct window onto that function.
- It is almost always included in a complete blood count, so you likely already have a baseline to compare against.
- Its normal range differs by sex, age and lab, which is why your own report's range matters more than a number pulled from elsewhere.
Sources
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
