Serum Ferritin

Definition

Blood protein that stores and transports iron throughout the body. Serum ferritin levels reflect total body iron stores and serve as a key marker for assessing iron status in health and disease.

How it works

Ferritin is the primary intracellular iron storage protein, and small amounts are released into the bloodstream. Serum ferritin measurement is the most reliable indicator of total body iron stores. Elevated ferritin suggests iron overload (hemochromatosis, repeated transfusions), while low ferritin indicates iron deficiency. However, ferritin is also an acute phase reactant, meaning it rises during inflammation, infection, or liver disease, potentially masking true iron status. Therefore, ferritin should be interpreted alongside other iron markers like transferrin saturation and serum iron to provide accurate assessment.

Role

Serum ferritin quantifies body iron stores and helps diagnose iron deficiency or iron overload conditions.

Examples

• Iron deficiency anemia diagnosis
• Hemochromatosis monitoring
• Transfusional iron overload assessment
• Thalassemia patient management
• Inflammation marker in chronic disease

Recommendations

Request ferritin testing when investigating anemia or iron disorders, always interpret results with transferrin saturation and serum iron levels, and repeat testing periodically if iron overload is diagnosed. If elevated, investigate causes including hemochromatosis, chronic transfusions, or inflammatory conditions.

Key takeaway

Serum ferritin is essential for diagnosing iron disorders but must be interpreted with other iron markers and considering inflammatory status.

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