“They often wake me in the middle of the night. They build in a matter of seconds and the pain is excruciating. It’s only in my right eye, like a red hot poker. I don’t know where to put myself. Sometimes I pace up and down the room holding my head, or just sit in the chair and rock. I cannot imagine a more severe pain.”

What is cluster headache?

Cluster Headache describes attacks of severe one-sided pain in the head, usually around the eye. The pain is associated with autonomic change in or around the eye. This means watering (including a runny nose), redness, eyelid closure, a small pupil, skin redness or sweating. Periods of attacks are known as bouts in which the pain is clustered (hence the name) over a few weeks or months.

Who gets cluster headache?

Cluster Headache is relatively uncommon but affects around 1 in 1000 people. Unlike other headache types, men are more commonly affected than women, at a ratio of around 3:1. It is the most severe pain known to humans. It can start at any age but often starts in younger adults.

What are the different types of cluster headache?

The more common type is episodic cluster (90%) headache. This means it comes and goes in bouts often seasonally: usually Spring and Autumn. Typically people suffer one or two bouts a year or every two years.

Chronic cluster is less common (10%). This is the same form of headache which persists for six months of more. In chronic cluster the pain may be continuous.

What are the symptoms of cluster headache?

Cluster Headache is extremely painful – so severe that it has been called the ‘suicide headache’.

The pain always stays on the same side within a bout but a minority of patients find cluster changes sides from bout to bout.

The pain is often described as searing, knife-like or boring in and around the eye. This reaches full force rapidly, within 5-10 minutes of onset, and each untreated attack typically lasts up to an hour but can be anything between 15 minutes and 3 hours.

In contrast to migraine, cluster pain causes restlessness or agitation and, because it can be so severe, can cause people to bang their head against the wall.

Pain often occurs at the same time every night (“alarm clock pain”) and typically within minutes of drinking alcohol.

Do I need any tests?

We do not advise routine brain scans for people with a typical presentation cluster headache. There have been studies which showed an excess of pituitary gland abnormalities in people with cluster, leading some experts to scan the brain and pituitary in patients with cluster headache which do not fit normal patterns or do not respond to typical treatment.

People taking verapamil to prevent cluster headache should have an electrocardiogram (ECG) before treatment starts and with every dose change, to rule out heart rhythm problems which can be caused or worsened by this drug.

What causes cluster headache?

Cluster, like migraine, is a primary headache: it arises from an error of nerve function. It is the most common form of the Trigeminal Autonomic Cephalgias (TACs) which are a type of headache completely unrelated to migraine. Although we do not fully understand the cause of cluster headache, we know that changes vascular system of the midbrain, also known as the posterior hypothalamus, occurs during attacks. This could account for sleep and seasonal variations.

What are triggers for cluster headache?

Usually there are no triggers, but alcohol can bring on an attack though zero alcohol does not abolish the bout. Cluster associates with smoking, though quitting smoking has not been shown to help. Other recognised triggers include exercise, strong odours (paint, nail varnish and petrol) and elevated environmental temperatures.

Addressing triggers is much less helpful for cluster than it is for migraine.

Will it get better?

Fortunately for many sufferers, particularly those with chronic cluster headache, cluster often improves in later life. Bouts of episodic cluster are by definition guaranteed to improve naturally, though tend to recur in the fullness of time.

What can I do to help myself?

There is no role for over the counter or simple painkillers in cluster headache: they do not work and often “muddy the water” with side effects. Effective treatment requires medical advice as prescription-only drugs are needed.

Cluster is uncommon so many non-specialist doctors have never seen a case. It may therefore be helpful to download selectively from www.ouchuk.org (Organisation for the Understanding of Cluster Headache) or bring this factsheet to show to your doctor.

What treatment can I take?

As this is a relatively rare condition, most people with cluster will need to see a headache specialist. Such experts are often saddened to encounter people with decades of cluster headache who have had neither diagnosis nor treatment for this seriously painful condition.
For episodic cluster, the usual starting regime is:

ā Sumatriptan 6mg injection for each episode of pain, taken as soon as possible after the start of pain. This normally works within minutes.
ā High dose Prednisolone (60-100mg) daily after breakfast for a week which should be rapidly tapered over 2-3 weeks. This aborts the bout in 70% and allows time for verapamil to start working.
ā Verapamil 80mg or 120mg three times daily, if ECG is normal. Continue until the bout is over.

Many respond to verapamil 120mg 3 times daily, but higher doses, up to 360mg three times daily, may be necessary. The effective dose should be continued for the usual duration of the cluster, then gradually tapered over a few weeks. If attacks recur, the dose can be increased again and reduced at 2 week intervals. Verapamil is usually well tolerated although constipation (which may be severe) acid indigestion and flushing can happen. Good dental care is important as gum bleeding from gum overgrowth (gingival hyperplasia) can occur.

Other Cluster Treatments

High flow (100%) oxygen is a possible alternative to sumatriptan particularly if you have more than two attacks per day. It is not always as convenient as Sumatriptan. Oxygen is delivered at 7-12 litres per minute through a non-rebreathing mask for 10-20 minutes. You should sit leaning forward with the mask firmly over your face ensuring it is a tight fit and there are no leaks. Your doctor will need to organise this via a Home Oxygen Order Form (HOOF). Some people find that oxygen simply time-shifts the attack. There has been much debate about the demand-valve oxygen system which was shown in one study to reduce the risk of hyperventilation.

Oral triptans should be avoided as they take too long to become effective.

Alternatives to verapamil include lithium, melatonin and topiramate.

Greater Occipital Nerve (GON) block is worth considering to abort a bout, as is a trial of indometacin as cluster can be mistaken for a paroxysmal hemicrania.

The new CGRP medications may have a use for the treatment of cluster headache but only one (galcanezumab) has been shown to be helpful so far and it has not been shown to be helpful for chronic cluster headache.

Can nerve stimulation help?

Some studies show that non-invasive stimulation of the vagus nerve via the GammaCore has been useful for reducing pain during attacks. It may have benefits in preventing chronic cluster headaches when used alongside other treatments.


Refractory cases may be considered for neurosurgical treatment with brain or occipital nerve stimulation.

Useful Contact:

The Organisation for Understanding Cluster Headache (OUCH UK)
Help line: 01646 651 979
Website: www.ouchuk.org
E-mail: info@ouchuk.org

This information is provided as a general guide only.  If you have any queries or concerns about your headaches or medications please discuss them with your GP or your National Migraine Centre Doctor.