What it measures
Haemoglobin is the protein inside red blood cells that carries oxygen from the lungs to the rest of the body. The test measures how much of it is in a litre of blood. It is part of a full blood count.
Why people test it
- The main measure used to check for anaemia, for example when someone feels tired or breathless.
- Checked when someone has heavy periods, gives blood often or eats little iron-rich food.
- Read alongside ferritin, B12 and folate to look into the cause of a low result.
- Testosterone therapy can raise haemoglobin, so it is monitored on TRT along with haematocrit.
- Endurance athletes often check it with ferritin, as low iron stores can lower haemoglobin.
Typical range
Ranges vary between labs, with the method used, age and sex, and your report shows the lab's own range. One NHS trust lab gives 130 to 180 g/L for adult men and 115 to 165 g/L for adult women. Source: Gloucestershire Hospitals NHS Foundation Trust: haematology reference ranges.
Finger-prick or vein?
A vein draw is usually advised. Finger-prick samples can clot or have their red cells burst (haemolyse) in the tube, which upsets blood count results.