What does high ferritin mean?

Upper reference limits vary by lab and assay, but are typically set at 200 µg/L in women and 300 µg/L in men [1]. WHO's screening thresholds for possible iron overload in otherwise healthy people are lower: above 150 µg/L in menstruating women and above 200 µg/L in men and non-menstruating women. In adults who are unwell, WHO uses above 500 µg/L [4].

Above 1,000 µg/L, ferritin is a non-specific marker of significant disease [1]. In hemochromatosis, ferritin below 1,000 ng/mL at diagnosis marks a low risk of advanced liver fibrosis [3].

WHO is clear that a high ferritin should prompt clinical and laboratory evaluation of the cause, and that ferritin alone should not be used to identify overload [4].

The table compares the main causes. The pattern of companion tests usually points the way [1].

• Inflammation and infection. Ferritin is an acute phase reactant and rises in any inflammatory state [1]. Check CRP (hs-CRP).
• Metabolic syndrome and fatty liver. The link between ferritin and metabolic syndrome is thought to run mainly through fatty liver [1]. A 2023 consensus named this metabolic hyperferritinaemia and tied it to higher cardiometabolic and liver disease risk [5]. Fasting insulin, HbA1c and triglycerides help show the pattern.
• Alcohol. An isolated ferritin below 1,000 µg/L from daily drinking is a common presentation, seen in 40% to 70% of people with chronic heavy alcohol use [1].
• Liver damage. In acute and chronic liver disease ferritin can exceed 10,000 µg/L, partly from damaged liver cells [1].
• Iron overload. HFE hemochromatosis, repeated transfusions and iron-loading anemias raise ferritin together with transferrin saturation [1].

Inflammatory signals increase ferritin production, and cellular damage releases ferritin into the blood [1]. One review argues that most ferritin in the blood leaks from damaged cells, which would explain why it correlates with so many diseases [6].

Inflammation also raises hepcidin, which traps iron in storage and lowers serum iron [7]. That is how someone can have high ferritin and low iron at the same time: the stores are full or overstated, but iron is not being released to the blood. In this situation iron deficiency can still be present underneath; ASH considers ferritin below 100 ng/mL or transferrin saturation below 20% as iron deficiency when inflammation is present [8].

When the inflammation settles, ferritin usually falls. The anti-inflammatory diet protocol covers the diet side of lowering chronic inflammation.

Transferrin saturation is the share of iron-binding sites on transferrin that carry iron. A normal saturation usually excludes abnormally increased iron absorption, and saturation above 45% in women and 50% in men is generally regarded as raised [1].

In people with two copies of the C282Y variant of HFE, EASL accepts transferrin saturation above 45% with ferritin above 200 µg/L in women, or above 50% with ferritin above 300 µg/L in men and postmenopausal women, as enough to diagnose haemochromatosis [2]. Other genotypes need MRI or biopsy evidence of liver iron [2].

The C282Y variant is most common in people of Northern European descent: 0.44% of non-Hispanic white participants in a large US screening study carried two copies, and most of those not yet diagnosed had raised ferritin [9]. Early diagnosis matters because treatment can prevent cirrhosis, liver cancer, diabetes and joint damage [2].

• Reactive high ferritin (inflammation, metabolic syndrome, alcohol): treat the underlying condition. Weight loss, less alcohol and managing inflammatory disease often bring ferritin down. There is no clear evidence that removing iron helps in metabolic hyperferritinaemia [5].
• Hemochromatosis: phlebotomy remains the mainstay of therapy [3]. Each session removes 400 to 500 mL of blood, about 200 to 250 mg of iron [1]. EASL targets ferritin below 50 µg/L during the induction phase and below 100 µg/L for maintenance [2].
• Diet plays a supporting role. People with confirmed overload are often advised to avoid iron supplements and iron-fortified products; a heme-rich pattern such as a carnivore diet is worth discussing with the treating clinician.

Searches such as "how to lower ferritin naturally" often lead to advice to give blood. Blood donation does lower iron stores, but if the high ferritin is from inflammation or liver disease, removing iron does not fix the cause. A clinician should find the cause first.