A fall is not usually caused by a single factor. Most falls by older persons result from the numerous, or complex interaction of intrinsic ( personal or host) factors, and extrinsic (environmental) factors. In other words, the likelihood of a fall, or injury from a fall is dependent on the characteristics that are inherent in individuals as well as environmental hazards. It is also related to the result of body changes by aging, disease or medication and changes of activity levels.