HEADACHE

pain in the upper portion of the head. Headache in one form or another probably is humanity's most frequently troublesome symptom, affecting nearly everyone at some time and inflicting recurrent discomfort on perhaps 1 person out of 10. Headaches vary widely in their intensity and in the seriousness of the underlying conditions that cause them. Most headaches occur because specific pain-sensitive structures in or around the head are overstimulated or damaged. Some of these are inside the skull, or intracranial; the remainder are in the tissues surrounding or covering the skull, or extracranial.