Almost everyone suffers from a headache occasionally. But some people suffer from repeated, frequent headaches.  What is headache? What causes it? What can be done about a headache? What research is being done on headaches?  The dictionary defines  headache simply as "a pain in the head." What most people mean by headache is a pain which lasts several minutes or hours.  It covers the whole head, or one side of it, or perhaps the front or the back of the head. To add to the confusion about a definition, some people call tight feeling in the head a headache. A headache is important because it can be the first warning of a serious condition which probably could be controlled if discovered early. If a person removes the warning, day after day, with a pain-killer, he may pass the point of easy control. The professional name for covering up a symptom is "masking" (,). A headache specialist once said, "Masking symptoms is not the best way of treatment." He compared taking a pain-killer for a headache before a cause is known with taking iron pills for anemia  while bleeding continues undiscovered. He added, "Sometimes it is wiser to stand still than to advance in darkness. A headache is important also because it interferes  needlessly with normal, happy living. The employee with a headache does less work. In a flash of temper he may upset his fellow workers or customers, causing a direct of indirect loss to his organization. The mother with a headache suffers and disturbs the family. She upsets her husband and children. What's the main idea of the passage?
Specialists know what a headache is. What's a headache and its effect. Everyone suffers from a headache occasionally. A headache can warn you of something serious.