The invention relates to a rotor for a pump, having at least one blade, the rotor being able to be actuated to rotate about an axis of rotation in order to convey a fluid in the axial or radial direction, the rotor being able to be deformed reversibly elastically in the radial direction between a first, radially compressed state and a second, radially expanded state which the rotor adopts without the effect of external forces, and a third state of the rotor being provided in which, in pumping operation under fluid loading, the rotor is deformed from the first state to beyond the second state.
