Ferritin is the single most useful blood test for understanding your iron stores — and one of the most commonly abnormal results we see at The Vesey. Low ferritin is a leading, fixable cause of fatigue, hair loss and poor exercise tolerance, especially in women; high ferritin has a different set of causes that are worth understanding rather than fearing. Here’s how to read your result, and when to test.
What Is Ferritin and What Does the Test Show?
Ferritin is the protein your body uses to store iron, mainly in the liver, spleen and bone marrow. A small amount circulates in your blood in proportion to your total stores — so a ferritin blood test is effectively a fuel gauge for iron.
That makes it more informative than a standard full blood count alone: your haemoglobin can still be normal while your iron stores are running on empty. This state — iron deficiency without anaemia — is extremely common and symptomatic, and it’s missed whenever only haemoglobin is checked.
Low Ferritin: Symptoms and Causes
Typical symptoms of low ferritin include persistent tiredness, hair shedding or thinning, breathlessness on exertion, restless legs, brittle nails, cold intolerance, brain fog and reduced exercise performance. Many people put these down to stress or age for years.
Common causes: heavy periods (by far the most frequent in premenopausal women), pregnancy, low dietary iron (including vegetarian and vegan diets without planning), reduced absorption (coeliac disease, low stomach acid, some medications), endurance training, and blood loss from the gut — which is why unexplained iron deficiency in men and postmenopausal women always needs investigation rather than just iron tablets.
Laboratory “normal” ranges typically start around 15–30 µg/L, but symptoms — particularly hair loss and fatigue — are commonly associated with levels below about 30–50 µg/L. That grey zone is where a GP review of the result in context, rather than a pass/fail flag, earns its keep.
High Ferritin: What It Means
Ferritin is also an inflammatory marker, so it rises with infection, inflammation, obesity, fatty liver disease, high alcohol intake and metabolic syndrome — these account for most mildly raised results. Persistently high levels (especially over 300–400 µg/L with a raised transferrin saturation) can indicate haemochromatosis, a common inherited iron-overload condition that is very treatable when caught early.
A raised ferritin should never be ignored, but nor does it usually mean iron overload. The follow-up is simple: repeat testing with transferrin saturation, liver function tests and a clinical review.
Getting Tested and Treated
At The Vesey, a ferritin test can be done on its own (individual blood tests from £32) or as part of a fatigue or hair-loss panel with full blood count, thyroid function, B12, folate and vitamin D — one blood draw, results in 24–48 hours, and a GP to interpret them and agree a plan.
If your ferritin is low, treatment isn’t just “take iron”: the right dose and schedule (alternate-day dosing is often absorbed better and tolerated better), vitamin C timing, treating the underlying cause, and a re-test at 8–12 weeks make the difference between feeling better and giving up on tablets that upset your stomach. Book online or call 0121 387 3727 — open 7 days, 8am–8pm, no referral needed.
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Frequently Asked Questions
What is a normal ferritin level in the UK?
Reference ranges vary by lab, but roughly 15–200 µg/L for women and 30–300 µg/L for men. Symptoms of iron deficiency such as fatigue and hair shedding are commonly associated with levels under 30–50 µg/L even when technically 'in range', which is why GP interpretation matters.
Can I have low ferritin with normal haemoglobin?
Yes — this is iron deficiency without anaemia and it is very common. Your body protects haemoglobin until stores are nearly exhausted, so a normal full blood count does not exclude iron deficiency. Ferritin is the test that shows your stores.
Why is my ferritin high?
Most mildly raised ferritin reflects inflammation, fatty liver, alcohol or metabolic factors rather than iron overload. Persistently high levels with raised transferrin saturation need checking for haemochromatosis. A GP can arrange the follow-up tests and interpret them.
How much does a ferritin blood test cost at The Vesey?
Individual blood tests start from £32, with results in 24–48 hours. Ferritin is also included in our fatigue and hair-loss panels alongside thyroid, B12, folate and vitamin D. No referral is needed — book online or call 0121 387 3727.