Trigger points are distinct areas of focal hyperirritability which give rise to areas of refered pain in well-defined areas of the musculo-skeletal system, sometimes remote from the point itself and not related to it by anatomically definable pathways. While the vast majority of pain manifestations from trigger points are related to the musculo-skeletal system, this need not be invariably so, as has been demonstrated in two of the cases cited, where injection of trigger points in the neck relieved chronic tinnitus. In all manifestations of chronic pain it is recommended that a diligent search be made for such trigger points.