Adjustable vehicle seat

A vehicle seat includes a seat part displaceable at least in the seat longitudinal direction; a back rest that is held on the seat part; and an adjustable head restraint held on the back rest and having a head cushion. For automatically adapting the head restraint correctly in terms of safety to seat adjustments carried out by a seat user, a medium reservoir of variable volume, communicating with a filling and discharge device, is integrated in the head cushion so that the cushion front face is shifted forwards during an increase in volume and is drawn back again as a result of a reduction in volume. The filling quantity introduced into the medium reservoir or drawn off from the medium reservoir is controlled depending on the seat setting by means of a control unit. The medium reservoir also may include a pressure limiter that allows a controlled outflow of the reservoir when a predetermined pressure value, caused by the impact of the head, is reached.