The present invention relates to a pump, in particular a blood pump having a proximal and a distal end and a pump housing arranged therebetween, a driveshaft arranged in an interior of the pump housing along the longitudinal direction, a conveying element arranged on the driveshaft, and a cannula. Here, the pump housing, the shaft arrangement and the conveying element are coordinated with one another in such a way that these guarantee the best possible efficiency and longevity of the pump.