Hemoglobin: What It Measures and Common Ranges

Hemoglobin is the protein in red blood cells that carries oxygen. Learn what it measures, typical ranges, and what abnormal values may indicate.

Hemoglobin (Hb) is the iron-containing protein inside red blood cells that carries oxygen from the lungs to body tissues.

Typical reference range

  • Male: 13.5–17.5 g/dL
  • Female: 12.0–15.5 g/dL
  • Pregnancy: ranges may differ; follow your laboratory's printed values.

What low hemoglobin may indicate

Low hemoglobin is broadly described as anemia. Anemia has many possible causes, including iron deficiency, vitamin B12 or folate deficiency, blood loss, chronic disease, or marrow conditions. Further tests may be needed to identify the cause.

What high hemoglobin may indicate

Higher-than-expected values may relate to dehydration, smoking, living at high altitude, or, less commonly, marrow conditions.

Hemoglobin is usually interpreted alongside hematocrit, MCV, RDW, and the WBC and platelet counts from a complete blood count.