Ferritin

Ferritin measures the amount of iron your body has in storage, giving the earliest read on whether your iron reserves are running low or too high. In adults, ferritin typically runs about 30 to 400 ng/mL in men and 13 to 150 ng/mL in women.

Ranges vary between labs, so compare to the range on your own lab report.

What ferritin measures

Ferritin is the protein that stores iron inside your cells and releases it when your body needs it. The amount circulating in your blood closely tracks your total iron reserves, so ferritin is the single best marker of how much iron you have banked. Because reserves fall before other iron markers shift, ferritin often flags a problem first.

What high or low levels mean

Low ferritin is the earliest and clearest sign of iron deficiency, often appearing before anemia shows up on a blood count. It commonly reflects blood loss, heavy periods, low dietary iron, or poor absorption, and it can leave you tired, pale, or short of breath.

High ferritin can point to iron overload, including hereditary hemochromatosis. But ferritin is also an acute-phase reactant, meaning it rises with inflammation, infection, liver disease, and heavy alcohol use, which makes a high result less specific. Follow up with your clinician if your ferritin is clearly outside the range, especially if paired with symptoms or abnormal iron studies. Repeat testing and additional markers help clarify the cause.

Ferritin FAQ

What does it mean if my ferritin is low but my hemoglobin is normal?

This usually means you have early iron depletion. Your stored iron has dropped, but there is still enough circulating to keep hemoglobin normal for now. Left unaddressed, it can progress to iron-deficiency anemia over time.

Can ferritin be high without iron overload?

Yes. Ferritin rises with inflammation, infection, liver disease, and alcohol use, so a high value alone does not confirm excess iron. Clinicians usually pair it with iron saturation and other markers to tell the difference.

Does fasting affect a ferritin test?

Ferritin itself is fairly stable and generally does not require fasting. However, it can rise temporarily during an acute illness or flare, so testing when you are well gives a more reliable picture of your true iron stores.

Read alongside Serum iron, Iron saturation, Total iron-binding capacity, and Hemoglobin for a full picture of your iron status.

Sources

• MedlinePlus Medical Encyclopedia, Ferritin blood test.

• Cleveland Clinic, Ferritin Test.