Cluster headache

Cluster headaches are excruciating attacks of pain in one side of the head, often felt behind the eye.

Sufferers often call them 'suicidal headaches' because they're so severe.

Cluster headache attacks

Cluster headaches begin unexpectedly. They're much more painful than migraines or any other type of headache.

They're called cluster headaches because sufferers usually get one to three of these attacks every day, for several weeks or months, before they subside. A pain-free period will follow, which sometimes lasts months or years, before the headache attacks start again.

Because of the intensity of the pain, some people will pace the room, rock, or bang their head against the wall out of frustration, restlessness and despair.

Read more about the symptoms of cluster headaches.

Types of cluster headache

There are two types of cluster headache, episodic or chronic (long-term).

• episodic – headache clusters are separated by headache-free periods of one month or more
• chronic – headache clusters are separated by headache-free periods of less than one month, or are not separated at all

About 10% of cluster headache cases are chronic.

Causes of cluster headaches

Research suggests that when a cluster headache happens, there's a lot more activity in an area of the brain called the hypothalamus. It's thought the hypothalamus releases chemicals that trigger the cluster headaches, possibly by causing blood vessels to widen, causing an increase in bloodflow to the brain.

It's not known what causes the hypothalamus to act in this way. However, in some people, cluster headaches are triggered by certain things, such as:

• drinking alcohol during the period that headaches occur – during headache-free periods, alcohol doesn't appear to trigger attacks
• an extreme increase in temperature (such as from exercising in hot weather)
• taking inhaled nitroglycerin – a medication that causes the blood vessels to enlarge

They are also more common in autumn and spring.

Who is affected

Cluster headaches are rare and affect around one in 1,000 people. Anyone can be affected, but approximately eight out of 10 people who have them are men and most are smokers.

Treatment and support

Cluster headaches can severely affect quality of life, so it's important that sufferers are referred to a specialist clinic for treatments to relieve and prevent the attacks.

Organisations such as Ouch UK and the Worldwide Cluster Headache Support Group offer advice and support.

Although cluster headaches can cause great suffering, they're not life-threatening. They can often be relieved with a medication called sumatriptan or with oxygen therapy. In some cases, preventative treatment may also be necessary.

Read more information about treating cluster headaches.

These treatments may vary in effectiveness from person to person. A few treatments may need to be tried before the attacks are under control.