Iron Blood Test: Procedure, Preparation, and What to Expect

The Test

Serum iron, ferritin, transferrin, TIBC, and transferrin saturation are measured via venous blood draw (typically from antecubital fossa).

Procedure

• Tourniquet applied; skin cleaned.
• Thin needle inserted into vein; blood collected into tubes.
• Tourniquet released; needle removed; pressure applied.
• Duration: <5 minutes. Minimal discomfort (brief pinch).

Preparation

• Fasting 8–12 hours preferred (iron levels fluctuate with meals).
• Avoid iron supplements 24 hours prior.
• Inform phlebotomist of bleeding disorders or anticoagulants.

Interpretation (Context-Dependent)

• Iron deficiency: Low serum iron, low ferritin, high TIBC, low TSAT.
• Anemia of chronic disease: Low serum iron, normal/high ferritin, low TIBC.
• Iron overload (hemochromatosis): High serum iron, high ferritin, high TSAT (>45%).

Results guide diagnosis of anemia, iron overload, or monitoring of therapy.