There is provided a fall detection system, comprising one or more sensors for monitoring the movement of a user of the fall detection system and for generating corresponding signals; means for determining a threshold from one or more measurements of the physical condition of the user; a processor for analysing the signals to identify a fall by the user; analysing the signals to identify a period of inactivity of the user following the fall; and comparing the length of the period of inactivity of the user with the threshold to determine the severity of the fall.