A bladder catheter includes a tube, wherein the tube has an insertion section for inserting into a urinary bladder through a urethra and wherein the tube has a connection section for connecting connection elements, wherein fluid can be drained from the urethra at the connection section via the insertion section, wherein a closable valve is arranged between the insertion section and the connection section in such a way that the discharge of fluid from the connection section can be prevented while the valve is closed.