Ferritin Blood Test
Reviewed
Also called: Serum ferritin, Ferritin level, Ferritin serum
Ferritin is an iron-storage protein; a blood ferritin result helps assess iron stores but also changes with inflammation and illness.
Specimen: Blood
Why this test may be ordered
- Investigating possible iron deficiency or overload
- Assessing anaemia with other tests
- Monitoring an iron-related condition or treatment
Preparation and collection
Follow the laboratory's instructions about fasting and collection time; requirements differ when ferritin is ordered with other iron studies. Report iron supplements and medicines, and do not stop them unless instructed.
A health professional usually takes a small blood sample from a vein. Collection normally takes only a few minutes.
Blood collection has a small risk of brief discomfort, bruising, light-headedness, or rarely infection at the needle site.
Understanding results
Ferritin should be interpreted with the laboratory interval, symptoms, CBC, other iron studies, inflammation, liver health, age, sex, and pregnancy status.
- Low ferritin: A low result can indicate depleted iron stores or iron deficiency. Limitation: Severity and cause require clinical assessment; ferritin is only part of the investigation. Next step: Discuss the result with the clinician and assess CBC, iron intake, blood loss, absorption, pregnancy, and the need for treatment or further investigation.
- High ferritin: A high result can occur with inflammation, infection, liver disease, metabolic conditions, cancer, or iron overload. Limitation: High ferritin does not by itself prove excess body iron. Next step: Discuss the result with the clinician and review other iron studies, inflammation markers, liver tests, history, and repeat or specialist testing when indicated.
- Inflammation, infection, liver disease, and some cancers can raise ferritin, so a result that is not low does not always exclude iron deficiency.
- Laboratory intervals vary and pregnancy or chronic disease changes interpretation.
What to do next
Follow-up may include CBC, transferrin saturation, serum iron/TIBC, inflammation markers, liver tests, or investigation for blood loss.
- Which reference interval and units apply to my result?
- Could medicines, supplements, illness, or sample timing affect this result?
- Do I need a repeat test or another test before any conclusion is made?