Cluster headaches are headaches that come on very suddenly with excruciating pain. Migraine headaches most often give the sufferers signs of the oncoming headache, like blurred or tunnel vision or nausea. However, cluster headaches rarely give such signs. Some of those who suffer from the headaches say they get a “shadow,” or small sensations foreshadowing pain in the area where the headache later hits.
The pain lasts for a period of time, generally 45 minutes to four hours, and then stops just as suddenly. However, cluster headaches will almost always come in series (hence the name). Therefore, the sufferer will likely have another headache a few hours or a day later. These “clusters” of headaches may go on for several days or weeks, or even months. Then cluster headaches may stop for months or years at a time, often to return. Some call them the “alarm clock” headaches, since they may occur at the identical time for several days in a row. They most commonly occur in the night or in the morning, although a few people get the headaches for a long period of time, perhaps lasting several days without relief. The pain is almost always unilateral, meaning that it hits on one side of the head or the other. There have been a few documented cases of the pain shifting from one side to the other within a cluster period, and even rarer cases of bilateral headaches.
The severity of the pain associated with these headaches causes some people to mistake them for signs of a brain tumor or multiple sclerosis. The patients have to be evaluated with a MRI or a CT scan to eliminate those possibilities.
The pain of cluster headaches has been likened to a hot poker in the eye or a bird of prey grabbing into the head. The pain often has the feeling of digging or boring into the head, often through the eye or behind the eye, and traveling down the neck. The original researcher who described the headaches said the pain was enough to drive a normal person to suicide. Indeed, others have nicknamed them “suicide headaches”.
As with other headaches, cluster headaches are either episodic (happening infrequently, from time to time, or sporadically, or with a month or more of remission between attacks) or chronic (occurring regularly, with a pattern, or occurring without a month of remission for a year or more).
As with most headaches, there is no single cause identified for triggering attacks. Eating chocolate or drinking alcohol may trigger them in some people. For some patients, being exposed to hydrocarbons, such as those found in petroleum solvents or perfumes may trigger the headaches. In other patients, a low level of tolerance for heat causes them to get the headaches when they are too warm, and for others, excessive exercise triggers and episode. The ailment is often noting in smokers.
These headaches are frequently misdiagnosed as migraines. Although there are no known lasting effects of the ailment, the discomfort is so great that doctors attempt to find medications or lifestyle altering behaviors to prevent attacks, since it requires strong medication to mitigate the pain of the headaches.