What does high ferritin mean?

What ferritin measures

Most of the iron in your body is busy - carried around in haemoglobin in your red blood cells. Ferritin is different: it is the storage form, holding iron in your liver, spleen and bone marrow until it is needed. A ferritin test therefore estimates your iron stores rather than the iron in active use.

Because ferritin reflects reserves, it is the single most useful marker for spotting iron deficiency early - stores fall before haemoglobin does. The flip side is that a high value can be caused by things other than iron, which is why context matters so much.

Typical UK reference ranges

Reference ranges vary slightly between laboratories and with age and sex, so always read your result against the range printed on your own report. As a rough guide for UK adults:

• Men: roughly 30–400 µg/L
• Women (pre-menopause): roughly 15–150 µg/L
• Women (post-menopause): roughly 30–300 µg/L
• A value above the upper limit for your group is flagged “high” - but how far above, and why, is what matters.

Why ferritin can be high even when iron is normal

Here is the part most people miss: ferritin is also an “acute-phase reactant”. That means it rises in response to inflammation, infection and tissue stress - independently of how much iron you actually store. A mildly raised ferritin during or after a cold, a flare-up, or intense training can simply reflect inflammation, not iron overload.

Other common contributors include regular alcohol intake, fatty liver, and being unwell recently. This is why a one-off high ferritin in isolation is rarely cause for alarm, and why doctors look at the bigger picture before drawing conclusions.

When high ferritin matters more

Persistently high ferritin - especially when paired with a high transferrin saturation - can point towards genuine iron overload, which is worth investigating. A genetic condition called haemochromatosis causes the body to absorb too much iron over time; it is one reason a doctor might check iron studies together rather than ferritin alone.

The key signals that warrant follow-up are a markedly elevated value, a value that stays high on repeat testing once any infection has settled, or a high ferritin alongside other abnormal iron or liver markers. None of these is something to self-diagnose - they are reasons to discuss the result with a clinician.

Reading ferritin alongside your other markers

Ferritin rarely tells the whole story on its own. Looking at it together with transferrin saturation, serum iron, and inflammation markers such as CRP helps separate “true” iron excess from an inflammation-driven rise. A high ferritin with a normal transferrin saturation and a raised CRP, for example, leans towards inflammation rather than overload.

This is exactly the kind of cross-marker pattern that is easy to miss when you read one number at a time. Tracking your results over multiple tests - rather than reacting to a single snapshot - makes a raised ferritin far easier to interpret.