The Total Iron Binding Capacity (TIBC) test measures the blood’s capacity to bind iron with transferrin, a protein that transports iron through the bloodstream. TIBC helps assess iron levels in the body, often in conjunction with serum iron and ferritin tests. Elevated TIBC may indicate iron deficiency, while low TIBC could be linked to conditions like chronic illness or iron overload. This test is useful for diagnosing anemia and evaluating iron metabolism disorders.