The invention relates to a blood pump for the invasive application within a body of a patient comprising a rotor (43, 27) which is drivable about an axis of rotation and is radially compressible or expandable and which has a hub (18, 28) and at least one impeller blade (14, 15, 16, 17, 29, 30) fastened thereto, as well as comprising a housing (19, 19′) which is compressible or expandable in the radial direction by an axial stretching or axial compression. The object of making both the rotor and the housing expandable and compressible in as simple a manner as possible is achieved in accordance with the invention in that a control body (21) is provided which passes through the hub (18) in the longitudinal direction and which is coupled to the housing on the distal side of the rotor such that it exerts pulling and/or compression forces on the housing by a movement in the longitudinal direction with respect to the housing.
