A steering column may include a steering spindle that is surrounded by a casing tube and is connected to a steering wheel, a guide clamp in which the casing tube is guided displaceably along a longitudinal axis of the steering spindle. The guide clamp may be mounted pivotably about a pivot axis in a holding part that is connectable to a chassis of the motor vehicle. The position of the casing tube may be adjustable relative to the holding part, and a blocking device may be arranged between the casing tube and the holding part. The blocking device may comprise a threaded rod engaged with a spindle nut. The spindle nut may be mounted in a rolling bearing. Rolling bodies of the rolling bearing may be at least partially surrounded by a magnetorheological fluid, and the blocking device may comprise an electromagnet.