There is provided a fall detection system comprising a user device configured to be worn or carried by a user, the user device comprising a proximity sensor for measuring the proximity of the user device to the ground or a floor; and a movement sensor for measuring the movements of the user; the fall detection system further comprising a processing unit configured to process the measurements from the movement sensor to detect a potential fall; activate the proximity sensor if a potential fall is detected; and process the measurements from the proximity sensor to determine if the user has fallen.