A personal hygiene device, in particular a toothbrush, has a handle, a treatment head mounted for relative movement with respect to the handle against a spring force when a treatment force is applied in at least one direction onto the treatment head, a treatment-force-measurement unit for determining the applied treatment force comprising an electrically powered coil, a coil core element, and a control circuit for determining a parameter indicative of the inductance of the coil, wherein the coil core element is arranged to be moved with respect to the coil when the treatment head is moved.