A device for measuring bladder pressure and/or for measuring intra-abdominal pressure within the body of a living being comprises a pressure measuring unit including a pressure sensor, and a urethral catheter comprising a balloon lumen, which connects a distal balloon for measuring internal pressure thereof to the pressure measuring unit, and a bladder lumen having a distal opening. The bladder lumen is, without detaching connectors, alternately connectable to a proximal urine outlet and separable therefrom, and the pressure sensor of the pressure measuring unit is connected to or is alternately connectable, without detaching connectors, to the bladder lumen.
