William O. Roberts, MD, a family physician at MinnHealth, in Minnesota, and vice president at the American College of Sports Medicine, likens a stress fracture to bending a paperclip back and forth: Eventually you get little cracks. While stress fractures are pretty common in the lower extremities -- the shin, foot, ankle-- they can also occur in the back or in the arms, says Nicholas A. DiNubile, MD, an orthopaedic consultant to the Philadelphia '76ers and the Pennsylvania Ballet.
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. Headaches can result from a wide range of causes both benign and more serious. Brain tissue itself is not sensitive to pain as it lacks pain receptors.
Cluster Headache-A particular type of headache that mainly affects men by a 6 to 1 ratio. It is characterized by intense but brief (30 minutes to 2 hours) pain in and around one eye occurring daily or several times per day in clusters that typically last for a couple of months.