A pressure differential across a blood pump and/or a flow rate of blood pumped by the blood pump is estimated based at least in part on impeller thrust load. A blood pump for a circulation assist system includes a housing forming a blood flow channel, an impeller, one or more support members coupled to the housing, a sensor, and a controller operatively coupled with the sensor. At least one of the one or more support members react a thrust load applied to the impeller by blood impelled through the blood flow channel by the impeller. The sensor generates output indicative of the magnitude of the thrust load. The controller is configured to process the sensor output to estimate at least one of a pressure differential across the blood pump and a flow rate of blood pumped by the blood pump.