In addition to the increased thrombotic risk associated with high platelet count, the decrease in antioxidant defense in iron deficiency may cause increased oxidant stress, which in turn may result in a tendency toward platelet aggregation. The abnormal platelet count and function observed in iron deficiency anemia could act synergistically to promote thrombus formation. Iron deficiency may contribute to a hypercoagulable state by affecting blood flow patterns within the vessels because of reduced deformability and increased viscosity of microcytic red blood cell.