The phenomenon of reactive hyperemia is used to demonstrate the potential clinical application of the continuous-wave NMR flowmeter in the measurement of the steady component of arterial blood flow. An ultrasound study of 15 normal volunteers showed steady flow to be small or nonexistent, particularly in the leg. Therefore, reactive hyperemia was used to induce a steady component in arterial blood flow. But since reactive hyperemia can be used to evaluate peripheral circulation in the human limb, the characteristics of reactive hyperemia are presented and studied for their own worth. A bi-directional Doppler ultrasound velocimeter was used to verify a normal steady component existing in limb blood flow as well as the nature of the change in blood flow caused by reactive hyperemia.