What it measures
Ferritin is the protein that stores iron inside the body's cells, and a small amount circulates in the blood. The blood level is the usual measure of the body's iron stores. It also rises with inflammation, infection and liver disease, whatever the iron stores.
Why people test it
- Checked when someone is tired, short of breath or pale, to look for low iron stores.
- Measured with heavy periods, in pregnancy and on vegetarian or vegan diets, when iron stores can run low.
- Used to monitor iron tablets or infusions, and to check for iron overload such as haemochromatosis.
- Endurance athletes, especially runners and women, more often have low iron stores, and ferritin is the usual check.
- Very hard sessions or illness can raise ferritin for a few days, as it rises with inflammation.
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's lab uses 30 to 337 µg/L for adults. Source: Leeds Teaching Hospitals NHS Trust: Blood Sciences Reference Range Database v3.20.
Finger-prick or vein?
A finger-prick sample is usually fine for ferritin.
