What this test measures
Ferritin is the protein that stores iron inside cells (mainly in the liver, spleen and bone marrow). The small amount of ferritin that leaks into blood mirrors total body iron stores quite closely — making serum ferritin the single most sensitive marker of iron deficiency. Indian labs report ferritin in nanograms per millilitre (ng/mL).
Unlike haemoglobin (which only falls once iron stores are exhausted), ferritin drops early — often years before clinical anemia develops. That makes ferritin the right test for catching iron deficiency in its reversible stage, before it harms your energy levels, exercise tolerance, hair, nails, and (in pregnancy) fetal brain development.
Why it matters
Iron deficiency without anemia is extremely common in India — particularly in adolescent girls, menstruating women, vegetarians, frequent blood donors, and people with subclinical GI blood loss (haemorrhoids, hookworm, peptic disease, undiagnosed coeliac). Symptoms are vague: fatigue, hair fall, brittle nails, restless legs, low exercise tolerance, low mood, breathlessness on exertion. By the time haemoglobin drops below normal, you have lost ~50% of total body iron and feel quite unwell.
Ferritin is also raised in inflammation (it is an acute-phase reactant), so a normal ferritin during active infection or autoimmune flare can mask underlying iron deficiency. In CKD, pregnancy, and chronic disease, ferritin and Iron Studies are interpreted together with CRP / clinical context.
How to prepare
No fasting required, but a fasting sample paired with Iron Studies in the morning is best if both are being measured. Continue your normal medications. If you have a current infection, recent vaccination, or active autoimmune disease, defer testing 1–2 weeks (inflammation falsely raises ferritin). Avoid heavy meat-based meals the night before if also testing serum iron, as this can transiently change the iron number.
Markers & reference ranges
Reference ranges below are typical adult values. Your lab's reported range may differ slightly based on the assay platform and patient demographics — always read your report against the range printed on it.
| Marker | Normal range | If low | If high |
|---|---|---|---|
| Serum Ferritin (ng/mL)[1][2][3] | Men 30 – 400 · Women (pre-menopausal) 13 – 150 · Post-menopausal 15 – 300 | < 30 ng/mL in an adult (or < 50 ng/mL during pregnancy) suggests iron deficiency. < 15 ng/mL is virtually diagnostic of iron deficiency. In symptomatic patients with values 30–50 ng/mL, a trial of iron supplementation is often justified, particularly in vegetarians, menstruating women, athletes, and those with hair loss / restless legs. | > 300 in women / > 400 in men: investigate for inflammation, recent infection, autoimmune flare, liver disease, alcohol use, metabolic syndrome / fatty liver, repeated transfusions, or iron overload (haemochromatosis). > 1,000 ng/mL with high transferrin saturation strongly suggests iron overload and warrants HFE genetic testing. |
How to read your ferritin result
| Ferritin (ng/mL) | Status | What it usually means | Action |
|---|---|---|---|
| < 15 | Severe iron deficiency | Iron stores essentially empty | Investigate cause (GI bleed, diet, menstrual loss); supplement; re-check at 3 months |
| 15 – 29 | Iron deficiency | Depleted iron stores | Iron supplementation; review diet |
| 30 – 50 | Low normal / functional deficiency | Symptomatic adults may benefit from treatment | Trial of iron if fatigued, restless legs, hair loss |
| 50 – 300 (women) / 50 – 400 (men) | Sufficient | Healthy iron stores | Routine annual re-check if at risk |
| > 300 / > 400 | Elevated | Inflammation, liver / metabolic disease, iron overload | Check transferrin saturation; rule out inflammation; consider HFE genetic testing if persistently high |
| > 1,000 | Significantly elevated | Significant inflammation, severe liver disease, iron overload, certain malignancies, COVID-19 / sepsis | Urgent evaluation |
Frequently asked questions
What is the difference between haemoglobin and ferritin?
Haemoglobin measures the iron-protein actively carrying oxygen in your blood. Ferritin measures the iron stored in your tissues. Ferritin drops first — long before haemoglobin — so it catches iron deficiency in its reversible early stage. Haemoglobin only falls once stores are nearly exhausted.
Do I need to fast for a ferritin test?
Not strictly — ferritin alone does not require fasting. If you are checking ferritin alongside Iron Studies, fast 8–12 hours and test in the morning.
My ferritin is 18 but my haemoglobin is normal — am I iron deficient?
Yes — this is "iron deficiency without anemia". Stores are depleted but blood production is still keeping haemoglobin in range. People at this stage often feel fatigued, breathless on exertion, have hair fall or restless legs. Oral iron supplementation usually helps, alongside investigating the underlying cause (diet, menstruation, GI blood loss).
Can ferritin be high if I have inflammation?
Yes. Ferritin is an acute-phase reactant — it rises during infection, autoimmune flares, recent vaccination, and even after vigorous exercise. A "normal" ferritin in someone with active inflammation can mask underlying iron deficiency. Re-check ferritin 1–2 weeks after the inflammation has settled, or pair it with Iron Studies and CRP for interpretation.
How long does it take ferritin to rise after starting iron supplements?
Ferritin can take 2–3 months to rise substantially even when haemoglobin has corrected. Plan a follow-up test at 3 months on treatment, not earlier.
My ferritin is 600 and I feel fine — is something wrong?
Moderately elevated ferritin in someone who feels well is often metabolic-related: fatty liver, alcohol use, or chronic low-grade inflammation. Persistent values > 300 with a high transferrin saturation (>45%) need workup for hereditary haemochromatosis, which is treatable but causes liver and heart damage if missed.
Why does pregnancy need a higher ferritin?
Pregnancy roughly doubles iron requirements. Ferritin below 30 ng/mL in pregnancy is treated as iron deficiency (some guidelines use 50 ng/mL as the threshold). Iron supplementation during pregnancy reduces maternal anemia and improves birth outcomes — almost universally recommended in Indian antenatal care.
How often should I check ferritin?
Once at baseline for at-risk groups (vegetarians, menstruating women, frequent blood donors, athletes, chronic disease). Re-check 3 months after starting iron therapy and 6–12 months thereafter. Annually as part of a routine health check if you have ongoing risk factors.
Related Hematology / Anemia tests
Tests commonly ordered alongside FERRITIN, or that help interpret an unexpected result.
Sources & references
- BSH — Ferritin and Iron Deficiency Guidelines · accessed 2026-05-29T00:00:00.000Z
- WHO — Serum Ferritin Concentrations for Assessing Iron Status (2020) · accessed 2026-05-29T00:00:00.000Z
- NIH MedlinePlus — Ferritin Test · accessed 2026-05-29T00:00:00.000Z
- NCBI StatPearls — Ferritin · accessed 2026-05-29T00:00:00.000Z
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