To summarize, brachialgia, which means pain in the arm, is a symptom complex. It can be produced by any one of a number of lesions affecting the sensory tracts supplying the arm. The site of the lesion can be traced by following the distribution and the quent location for the nerve irritation is in the intervertebral foramen, and anatomical and physiological considerations clarify the relative ease with which sensory disturbances can be produced here. Affections of the intervertebral foramina are usually associated with clinical evidences of pathology in the cervical spine. Treatment must be directed to the primary etiological factor, but hyperextension of the spine will tend to reduce the compression of the nerves within the intervertebral foramina.