Cluster Headaches
Cluster headaches occur in less than 1% of the population, and more than 80% of cluster headache sufferers are males. The cause of cluster headaches is unknown. A cluster headache is primary headache pain, and no evidence of secondary headache is suspected.
Primary and Secondary Headaches
Cluster headaches are defined by these characteristics:
- Extremely severe, one-sided (unilateral) pain around one eye (the orbit).
- Pain lasts from 15 minutes to 3 hours.
- Rapid onset of pain.
- Recurrence frequency ranges from once every other day to eight times per day.
- Attacks may occur at any time but most often emerge at night.
- Alcohol, sleep, and emotional stress are known triggers.
In addition to the excruciating, stabbing quality of the pain, the following symptoms accompany the headache:
- The eye that is the focal point of the pain becomes deeply reddened with profuse watering.
- Nasal congestion, runny nose, lowered upper eyelid, constriction of the pupil, and facial sweating may also occur.
- Headaches occur in series at regularly timed intervals -- often daily for weeks or months, hence the name cluster headache.
Cluster headaches have hallmark features:
- The intensity of pain is described as excruciating or very severe.
- While migraine headache sufferers reduce their activity, the person with a cluster headache responds with agitated pacing or sitting and rocking the head and trunk.
- Some sufferers provoke other pain sensations as a distraction from the pain of the cluster headache.
The International Headache Society (IHS) has established criteria for diagnosing cluster headaches. To meet these official criteria, the headache must have these characteristics:
- The occurrence of at least five headache attacks
- Severe one-sided (unilateral) pain in the eye or areas surrounding the eye
- Without treatment, lasts 15 minutes to 3 hours
Furthermore, the headache must be associated with at least one of the following signs on the side that the pain occurs:
- Reddened eyeball
- Excessive tears from the eye
- Nasal congestion
- Runny nose
- Facial sweating
- Small pupils
- Lowered upper eyelid
- Eyelids become puffy
