Hemoglobin is the iron-rich protein inside red blood cells that carries oxygen from your lungs to every part of your body. It is the main number doctors look at to diagnose anemia.
- Normal range (adults)
- Men 13.5–17.5 g/dL (135–175 g/L) · Women 12–15.5 g/dL (120–155 g/L)
- Sample
- Blood
- Fasting
- Not usually needed
- Also called
- Haemoglobin, Hb, HGB, H.G.B
Hemoglobin normal range
| Group | g/dLConventional units: US, South Asia | g/LSI units: UK, Europe, Australia, international |
|---|---|---|
| Men | 13.5–17.5 | 135–175 |
| Women | 12–15.5 | 120–155 |
Your report may use either unit system; labs in the Gulf often print both. Ranges also vary slightly between laboratories, so the range printed on your own report is the one to go by.
Why is the Hemoglobin test done?
It is part of every Complete Blood Count. Doctors check it during routine check-ups, in pregnancy, before surgery, and when someone feels tired, breathless or looks pale.
What does a high Hemoglobin level mean?
A high hemoglobin means your blood is thicker than usual. Mild rises are often caused by dehydration or smoking; a persistent high value can increase the risk of clots and needs to be explained.
Common causes
- Dehydration (the blood becomes concentrated)
- Smoking
- Living at high altitude
- Long-term lung or heart disease that lowers oxygen levels
- Testosterone or anabolic steroid use
- Polycythemia vera, a rare bone-marrow condition
Diet and lifestyle tips
- Drink enough water through the day, especially in hot weather
- Stop smoking
- Do not take iron supplements unless your doctor prescribes them
- Limit alcohol
What does a low Hemoglobin level mean?
A low hemoglobin is called anemia. Your body gets less oxygen, which can cause tiredness, weakness, breathlessness, headaches, pale skin and a fast heartbeat.
Common causes
- Iron deficiency (the most common cause worldwide)
- Heavy periods or blood loss from the stomach or bowel
- Low vitamin B12 or folate
- Pregnancy
- Long-term kidney disease or inflammation
- Inherited conditions such as thalassemia trait
Diet and lifestyle tips
- Eat iron-rich foods: red meat, liver, chicken, fish, lentils, chickpeas, beans, spinach and fortified cereals
- Have vitamin C (citrus, guava, tomatoes) with meals to absorb more iron
- Avoid tea and coffee for an hour around meals; they block iron absorption
- Include B12 and folate sources: eggs, dairy, meat, leafy greens
- Take iron tablets only after your doctor has confirmed the cause
When should you see a doctor?
See a doctor if your hemoglobin is below the normal range, especially if you feel short of breath, dizzy or have chest pain. Very low values (around 7 g/dL or less) need prompt attention. A persistently high value should also be checked.
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This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.