Abstract: Systems, methods, devices, and other techniques for assessing a fluid system of a patient. A fluid evacuator applies compression to a cuff on a limb of the patient, and measures a pressure of the cuff during the compression to obtain a pressure response curve. The pressure response curve can be analyzed to identify an incompressible region, where the incompressible region is a portion of the pressure response curve indicative of a bodily fluid having been substantially evacuated from at least a portion of the limb as a result of the compression.