Facts about Cluster Headaches

• The pain of a cluster attack increases rapidly over five minutes, and can last for over an hour.
• The pain of a cluster attack is excruciating, explosive, and deep, and has been likened to “having a red hot poker driven slowly through your eye”; always on one side, although the side can shift from one attack to another.
• Cluster attacks are also accompanied by a one-sided droopy eyelid, teary eye and runny nose.
• Cluster headaches originate in the hypothalamus, a small pea-shaped organ in the exact center of the head that also regulates the circadian rhythm (sleep scheduling) and interfaces between the nervous system and the endocrine (hormone) system.
• The pain in cluster headache comes from the trigeminal nerve, which transmits sensation from the face.
• Most people get their first attack in their twenties, but some people not until they are much older.
• Cluster attacks are “clustered” in “cluster periods” that last for several weeks to months the same time each year, rather than being spread out like regular headaches.
• Cluster attacks also occur predictably at the same time every day, often at night, with the onset of dream sleep.
• In the chronic form of cluster headache, there are no pain-free periods, and attacks occur year-round.
• Only 0.4% of the population has cluster headache—about a million people in the United States. Cluster headache is much less common than migraine headache or tension headache.
• Men are four times more likely than women to be affected, unlike migraine, which is more common in women.