Ferritin
Ferritin is the body's main iron-storage protein. A low value usually means iron stores are depleted; a high value can mean inflammation or iron overload.
What it measures
Ferritin is the protein your body uses to bank iron — most of it inside the liver, bone marrow and spleen. A blood ferritin level estimates how much iron is in storage, before the haemoglobin level (the iron in active circulation) starts to fall. That makes ferritin one of the earliest signals of iron-deficiency, often months before anaemia is visible on a CBC.
What a high value can mean
- Inflammation or infection — ferritin is an acute-phase reactant; any active inflammatory process can raise it without iron overload.
- Liver disease — hepatocytes release ferritin when injured.
- Iron overload — hereditary hemochromatosis or transfusion-dependent conditions.
- Some cancers — lymphoma, leukaemia, hepatocellular carcinoma.
What a low value can mean
- Iron-deficiency anaemia — the textbook reading, usually paired with low haemoglobin, low MCV and low transferrin saturation.
- Heavy menstrual bleeding, pregnancy, GI bleeding — common sources of chronic iron loss.
- Low dietary iron / malabsorption (coeliac disease, gastric bypass, vegan diets without supplementation).
When to discuss with a doctor
If your ferritin is below 30 ng/mL or above 500 ng/mL on a routine test, we recommend discussing it with your primary-care doctor within the next visit cycle. Ferritin below 15 ng/mL alongside fatigue, hair loss or restless legs warrants a focused consultation. Mediora.AI surfaces these thresholds inside your report; we do not diagnose iron deficiency on your behalf.