About Ferritin
Ferritin is the protein your body uses to store iron, and your ferritin level is the most sensitive early indicator of iron status — it can be depleted for months while your hemoglobin and red blood cell count still appear 'normal.' Low ferritin is the most common explanation for fatigue, hair loss, breathlessness, and poor concentration that a standard blood count misses. Very high ferritin, conversely, signals iron overload, active inflammation, or liver disease.