Complete blood count
Haemoglobin
Haemoglobin is the protein inside red blood cells that carries oxygen from your lungs to the rest of your body. It is the number most often used to decide whether someone is anaemic.
Typical adult reference range
Roughly 13.5 to 17.5 in men, 12.0 to 15.5 in women · g/dL
Ranges vary between laboratories and by age, sex and method. Always read your own result against the range printed on your own report.
What a high result can mean
A raised haemoglobin can come from dehydration, which concentrates the blood, from living at altitude, from smoking, from sleep apnoea, or less commonly from a bone marrow condition that makes too many red cells.
What a low result can mean
A low haemoglobin is called anaemia. Iron deficiency is the most common cause worldwide, but low B12 or folate, ongoing blood loss, kidney disease, and chronic inflammation all cause it too. The cause matters far more than the number, because the treatments are completely different.
What commonly affects this result
Hydration at the time of the draw, altitude, smoking, pregnancy, and recent blood donation.
Questions worth asking your doctor
- Do we know why my haemoglobin is where it is, not just that it is low?
- Should we check iron, B12 and folate before starting any supplement?
- Is this a change from my previous results, or has it been stable?
See what your own results say
Upload your blood test and get a plain English summary of every value on it, with the questions worth raising at your next appointment.
Analyse my resultsThis page explains what a test measures. It is general information, not medical advice, and it cannot tell you what your own result means. Reference ranges differ between laboratories, and results are only meaningful alongside your history, your symptoms and your other results. Always discuss your results with your doctor.