What Does Hemoglobin Mean?
Hemoglobin is the protein in red blood cells that carries oxygen throughout your body. Low levels are commonly linked to fatigue, weakness, and iron deficiency.
What Hemoglobin Measures
Hemoglobin (Hgb) is a protein inside red blood cells that binds to oxygen in your lungs and delivers it to tissues throughout your body. It also carries carbon dioxide back to the lungs. When hemoglobin is low, your body gets less oxygen, which often shows up as tiredness, shortness of breath, or pale skin.
Normal Ranges
Men13.8–17.2 g/dL
Women12.1–15.1 g/dL
Mild anemia< 12 g/dL (women) / < 13 g/dL (men)
Severe anemia< 8 g/dL
Reference ranges may vary slightly by lab. Always use the range provided on your specific test report.
What Affects Your Hemoglobin Level
- Iron deficiency (most common cause of low hemoglobin)
- Vitamin B12 or folate deficiency
- Chronic blood loss (heavy menstruation, GI bleeding)
- Chronic disease or inflammation
- Dehydration (can artificially raise hemoglobin)