Types Of Headaches Cluster

Cluster headaches are exceptionally severe headaches that occur for no known cause. Cluster headaches are rarer than migraines, affecting only 69 out of every 100,000 people (less than one percent). Unlike most severe headaches, cluster headaches affect more men than women; in fact, men are six times more likely to develop cluster headaches than women.

Cluster headaches can strike at any age, but usually develop in men between the ages of twenty and fifty. Women are more likely to develop severe cluster headaches after age fifty.

Cluster Headache Symptoms

Cluster headaches start suddenly, with little warning. Within two to fifteen minutes of symptom onset the pain become excruciatingly severe. Cluster headaches usually start around or above the eye or temple.

Cluster Headaches - Types of Headaches

Cluster headaches cause severe unilateral pain, meaning the headache occurs on only one side of the head. In the majority of cases cluster headaches always occur on the same side of the head. In fifteen percent of cases cluster headaches may switch from one side of the head to the other.

In addition to headache pain, ten to twenty percent of people with cluster headaches report “ice pick” pain – a severe, stabbing pain that stands out from the other headache pain. The ice pick may strike once or repeatedly. The onset of ice pick pain appears to come just prior to the end of a cluster headache. Once the headache pain starts to diminish, cluster headache symptoms clear up within minutes.

Physical signs of impending cluster headaches often include itchiness and/or nasal discharge from the nostril on the affected side of the face. When the severe headaches end, the eyelid on the “headache” side of the face is often droopy and the pupil is constricted (a medical condition referred to as Horner’s Syndrome).

The pain of these extremely severe headaches is more intense than migraine pain. Cluster headaches that start at night wake people from sleep; the average time of onset for nighttime cluster headaches is two to three hours into the sleep cycle, usually during the REM, or rapid eye movement, sleep phase.

The pain caused by cluster headaches is so severe that headache sufferers cannot lie or sit still. People in the grip of these severe headaches often pace during attacks, and the pain is so intense that some people bang their heads in an attempt to get some relief.

Duration and Frequency of Cluster Headaches

Cluster headaches usually last between thirty minutes to two hours, with the average headache lasting 45 minutes. Occasionally, severe headaches may resolve in as little as ten minutes, while in some rare cases cluster headaches can last for several hours.

Cluster headaches are so named because attacks “cluster” in four to eight week cycles. Frequency of attacks vary among individuals. Some people experience as many as six severe headaches a day, while others report only one cluster headache a week. On average, cluster headache sufferers can expect one to two severe headaches a day for the duration of the cycle.

Often the severe headaches that characterize cluster headaches can be predicted ahead of time. In 85 percent of cases cluster headaches will occur at the same time of day for an entire cycle.

Ninety percent of people living with cluster headaches have pain-free periods between clusters of severe headaches. The remaining ten percent develop chronic cluster headaches, which last an average of four or five years before resolving. Some research suggests that the older the individual is at the onset of cluster headaches, the greater the chance that he or she will suffer chronic severe headaches.

Causes and Triggers of Cluster Headaches

The cause of cluster headaches is unknown, although it is suspected that the hypothalamus is involved. The hypothalamus is the area of the brain that influences eating and sleeping patterns, sexual activity, and many chemical and hormone functions. During cluster headaches, the area of the hypothalamus on the headache-affected side of the brain is unusually active.

A number of possible cluster headache triggers have been identified. Noise, bright light, and odors, which often trigger migraines, do not appear to set of cluster headaches. Instead, severe cluster headaches may be triggered by:

  • alcohol (many cluster headache sufferers appear to be sensitive to alcohol’s effects)
  • allergies and hay fever
  • exposure to temperature changes
  • head injuries
  • relaxation
  • smoking
  • stress.

In some instances, it appears eating specific foods triggers cluster headaches. Eggs, chocolate, and diary products have all been associated with cluster headaches.

Treatment for Severe Headaches

Cluster headaches develop so rapidly that oral medications are not usually effective; the severe headaches are ending before the medication takes effect. As a result, inhalers are often used to treat cluster headaches.

In addition to the medications listed below, some cluster headache sufferers find that intense exercise right at the onset of their severe headaches lessens the severity of or even stops the headache completely. Intriguing though this is, exercise does not work for all cluster headaches.

Calcium Channel Blockers: Calcium channel blockers such as verapamil relax the muscles in blood vessels, allowing blood vessels to dilate. Verapamil is also used to treat migraines.

Ergotamine Inhalers: Ergotamine constricts blood vessels in the outer brain layers and the scalp, and provides relief from cluster headaches in approximately 85 percent of cases. Ergotamine use must be limited, however, to avoid nausea, rebound headaches, and other side effects.

Lithium: Lithium has proven an effective medication for chronic cluster headaches. Dosage needs to be carefully monitored to avoid unwanted side effects, which include liver damage.

Oxygen: In approximately eighty percent of cases pure oxygen administration can stop cluster headaches if administered at symptom onset. Oxygen has proven very useful for nighttime headaches.

BOTOX® and Cluster Headaches

Some evidence now exists that injections of botulinum toxin, brand name BOTOX, Can provide cluster headache relief. BOTOX is commonly used as a cosmetic treatment to smooth wrinkles. More studies are required to verify whether BOTOX can also be used to treat severe headaches.


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Beers, M.H. (ed). Cluster headaches. The Merck Manual of Medical Information, 2nd Home Edition. Merck Research Laboratories, NJ, 2003.

National Library of Medicine. (updated 2002). Cluster headaches. MedlinePlus Medical Encyclopedia.

National Library of Medicine. (updated 2002). Horner’s syndrome. MedlinePlus Medical Encyclopedia.