Ferritin
Serum Ferritin
What this test measures
Ferritin shows how much iron your body has stored. Iron is needed to make haemoglobin in your red blood cells. This test helps check for iron deficiency or iron overload.
Understanding the numbers
Typical range: Men: 24-336 µg/L | Women: 11-307 µg/L
Below 30 µg/L indicates iron deficiency per NICE guidelines. Ferritin can also rise with inflammation or infection.
- Deficient: 0–15 µg/L
- Low stores: 15–30 µg/L
- Normal: 30–300 µg/L
- Raised: 300–1000 µg/L
Key numbers
- 30 µg/L — NICE threshold for iron deficiency
- 300 µg/L — Upper limit in men; consider causes of rise
- 1000 µg/L — Very raised — think haemochromatosis / inflammation
- 45 µg/L — Iron-deficiency symptoms can occur up to ~45
NICE CKS anaemia sets 30 µg/L as the threshold for iron deficiency. Ferritin is an acute-phase protein — it rises with infection, inflammation and liver disease, so 'normal' ferritin with active inflammation does not rule out iron deficiency. A transferrin saturation helps.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a higher-than-normal result can mean
- You may have too much iron stored in your body
- Can be raised temporarily by inflammation or infection
- Very high levels may suggest a condition called haemochromatosis
- Your GP may do more tests if levels are very high
Questions you could ask your GP
- What is causing my low iron levels - could it be blood loss or diet?
- What dose of iron tablets should I take, and how long for?
- Which foods are best for boosting my iron levels?
- Do I need any tests to rule out internal bleeding?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
Low ferritin, heavy periods
Aanya was tired and breathless on stairs. Her ferritin was 8 µg/L, haemoglobin 108 g/L, and she had heavy periods.
What the GP said: “This is iron deficiency anaemia. We'll start iron, sort out the heavy bleeding, and recheck in three months. Take the iron with vitamin C (orange juice) and away from tea or coffee, which block absorption.”
What happened next: Six months on iron and a Mirena coil, her ferritin was 62 and she felt much better.
A low ferritin is the earliest sign of iron deficiency — before haemoglobin drops. Fatigue, hair loss, restless legs and brain fog often respond to iron even when the haemoglobin is still normal.
Low ferritin, coeliac diagnosis
Ian's ferritin was 12 µg/L despite eating plenty of red meat. He had occasional loose stools and bloating.
What the GP said: “Iron deficiency in a man — especially without obvious blood loss — needs investigation. I'll check coeliac antibodies and, depending on those, we may need to look at the gut.”
What happened next: Anti-tTG was strongly positive and a biopsy confirmed coeliac disease. A gluten-free diet and iron brought his ferritin to 80 over nine months.
Low ferritin in a man, or in a woman without heavy periods, always needs a cause. Coeliac disease, stomach ulcers and bowel cancer are all possibilities — and they matter more than the ferritin itself.
Very high ferritin — haemochromatosis
George's ferritin was 780 µg/L. His transferrin saturation was 68%. His brother had been diagnosed with haemochromatosis the year before.
What the GP said: “This combination — high ferritin and high saturation, and a family history — strongly suggests hereditary haemochromatosis. I'll check the HFE gene and refer to the specialist clinic.”
What happened next: HFE was positive (C282Y homozygous). George began venesection (removing a unit of blood every couple of months), which brought his ferritin down over a year.
A high ferritin with a high transferrin saturation, especially with a family history, points to hereditary haemochromatosis. Early treatment with venesection prevents liver, heart and joint damage — and family members can be screened.
Raised ferritin — inflammatory, not iron overload
Meena's ferritin was 420 µg/L. Her CRP was 45 and she had active rheumatoid arthritis. Her transferrin saturation was 18%.
What the GP said: “Ferritin rises with inflammation, and your rheumatoid flare is driving this up. Your low transferrin saturation shows you are not actually iron-overloaded. As the arthritis settles, ferritin will come down.”
What happened next: Methotrexate was started for the rheumatoid; three months later her ferritin was 160 and CRP 6.
Ferritin is an acute-phase protein. A raised ferritin during inflammation or infection does not mean iron overload. Pair it with transferrin saturation to get the real picture — high ferritin + low saturation = inflammation; high ferritin + high saturation = real iron overload.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.