By Pure Matters
Like the ringing of an alarm clock, a cluster headache announces itself every morning or night.
If you suffer from cluster headaches, you know that timing is everything. These headaches -- called "cluster" because of their pattern of striking in groups or clusters -- hit at the same time of day for a period of weeks or months, then vanish as suddenly and as mysteriously as they appeared.
The pain of cluster headaches is very intense. Most sufferers cannot sit still and will often pace during an acute attack. Often described as having a burning or piercing quality, the pain may be throbbing or constant. The scalp may be tender.
Cluster headaches, which are generated by swelling of blood vessels in the head, generally reach their full force within five to 10 minutes after onset. The attacks are usually very similar, varying only slightly from one attack to another.
Malfunction is the trigger
Researchers now believe that cluster headaches, as well as migraines, are triggered by a malfunction of neurotransmitters --in particular, serotonin-- which control the action of the blood vessels in the head and neck.
Although the pain of a cluster headache starts suddenly, people usually have a bit of warning that one is on the way. That warning is often a feeling of discomfort or a mild, one-sided burning sensation. Most cluster headaches last only 30 to 45 minutes, but some range from a few minutes to several hours. The headache will disappear only to recur later that day; most sufferers get one to four headaches per day during a cluster period.
Because they occur so regularly, generally at the same time each day, they have been dubbed "alarm clock headaches."
The headache periods can last weeks or months and then disappear completely for months or years. The cluster headache sufferer has pain-free intervals between series. Many cluster headaches occur in the spring or autumn. Because of this, cluster headaches are often mistakenly associated with allergies or business stress. The seasonal relationship is unique for each sufferer. In about 20 percent of cluster sufferers, the attacks may be chronic--they are present throughout the year and do not occur in groups, thus making the control of these headaches more difficult.