The most incapacitating of all vascular headaches, this type lasts from 15 minutes to 3 hours and typically occurs in clusters, coming and going repeatedly over several days or weeks and then disappearing for months or even years.

Often starting during sleep, they cause excruciating, stabbing pain on one side of the head, usually behind or around one eye. Some people liken the pain to a hot poker stabbing the eye. Cluster headaches are far more cothmon in men than in women, especially among those who are heavy smokers and frequent alcohol users.

Eliminating these habits may banish the headaches. In addition, keeping a diary of food and lifestyle factors may reveal that some of the factors known to trigger migraines can prompt cluster headaches as well.

The pain causes a bandlike pressure around the head and may be accompanied by a sense of tightness in the head, neck, and shoulder muscles. They often begin in the afternoon or evening and produce a steady pain. Prevention is the best approach; relaxation techniques, such as biofeedback, massage, meditation, and visualization, work for many people. Another recommendation is to eliminate from the diet all foods and drugs that contain caffeine, which can increase tension and anxiety, thus contributing to headaches.

Headaches also may be due to sinusitis, an inflammation of the lining of the sinus cavities, This causes a deep, dull ache around the eyes and sometimes in the forehead and ears. A good diagnostic clue is that the pain tends to worsen when you bend over. So-called rebound headaches can result from overuse of over-the-counter analgesics, prescription pain medications and sedatives, and caffeine (which is a common ingredient in such drugs), resulting in a vicious cycle of growing tolerance and increasing dependence.

These tend to be mild to moderate headaches.Although you may have to go through a painful, headachy period for a week or more to withdraw from dependence on these drugs,
you will feel better in the long run. Dental problems, too, can cause very severe one-sided headaches, which may feel exactly like migraines or clusters, especially if your tooth is abscessed. The many other factors that can cause headaches include squinting for
hours in bright sun, eyestrain, hunger, excessive alcohol consumption, and too little or too much sleep.