Hemoglobin is the iron-rich protein in red blood cells that carries oxygen from your lungs to the rest of your body. When it falls below the normal range, the condition is called anemia.
Normal hemoglobin ranges
Typical adult ranges are roughly 13.5 to 17.5 g/dL for men and 12.0 to 16.0 g/dL for women. See the full breakdown on our hemoglobin guide.
Common causes of low hemoglobin
- Iron deficiency — the most common cause worldwide, often from blood loss or low dietary iron. Check ferritin and serum iron.
- B12 or folate deficiency — look for a high MCV alongside low hemoglobin.
- Chronic disease or inflammation, kidney disease, or blood loss.
Symptoms to watch for
Fatigue, pale skin, shortness of breath, dizziness and a fast heartbeat. Mild anemia may cause no symptoms at all and is found only on a blood test.
What about high hemoglobin?
A high value can simply mean dehydration, but it can also reflect smoking, living at altitude, or a bone marrow condition, so it is worth discussing if it persists.
You don't have to interpret a single number alone. Upload your full lab report and Lab Lens will explain every value in plain English, or browse all our lab test guides.
This article is for general education only and is not medical advice. Reference ranges vary between laboratories — always read your result against the range on your own report and discuss it with your doctor.