A pressure sensor for providing an indication of the pressure applied by a bandage to a human or animal body. The sensor comprises an elongate, flexible support strip (63) adapted to be placed between a bandage and the body, the support strip carrying a flat pressure sensitive portion (69) whose electrical properties vary with applied pressure perpendicular to the general plane of the support strip, and also carrying flat, flexible conductors (65, 66) for connecting the pressure sensitive portion to a supply of electricity and to means for providing an indication of the applied pressure (71). In some arrangements an integrated battery, circuitry and display may be provided on the support strip.