Cluster headache

Cluster headache is one of the most painful conditions known to humans. Women who experience cluster headache describe the pain as worse than childbirth.

On this page you can find the following information:

Key points about cluster headache

  1. It is characterised by extreme pain on one side only, usually around or behind your eye.
  2. You may have up to 8 attacks per day, with each attack lasting between 15-180 minutes. 
  3. The pain is accompanied by feeling restless or agitated, other symptoms may include a drooping eyelid, redness of the eye, watering of the eye and a runny nose – all on the same side as the pain. 
  4. Pain typically occurs in ‘cluster bouts’ lasting 6–12 weeks, with a symptom free period before the next bout, and often starts at the same time of the day or night each time.
  5. Treatment can provide immediate relief when pain is experienced or be preventive medicine taken for the duration of the cluster bout.

What are the symptoms of cluster headache?

  1. It is characterised by strictly unilateral (one-sided) extreme pain
  2. The distribution of pain is usually around or behind the eye.
  3. People may have up to 8 attacks per day, with each attack lasting between 15-180 minutes. 
  4. The pain is accompanied by restlessness or agitation. 
  5. Pain is accompanied by autonomic symptoms in varying combinations on the same side as the pain, eg, drooping of the eyelid, redness of the eye, watering from the eye, runny nose. 
  6. Pain typically occurs in ‘cluster bouts’ lasting 6–12 weeks with a symptom free period before the next bout. 
  7. Pain may follow a striking circadian rhythmicity. For example, if a patient is woken up with pain at 1 am in the middle of the night, the pain may recur at the same time the following night and so on for the duration of the ‘cluster bout’.

What causes cluster headache?

The mechanisms behind cluster headache are complex and are not completely understood. The most widely accepted theory is that cluster headache is characterized by activation of a part of the brain called the hypothalamus with secondary activation of the trigeminal-autonomic reflex network leading to all the classical symptoms of cluster headache. This is a rare headache disorder and unfortunately, because it is rare, it may take several years before the diagnosis is made. 


If you are experiencing cluster headaches they may just happen for no apparent reason. However some people find that certain things act as a trigger and if you know what triggers your headache you are best to avoid it while you are in a cluster of headaches. Triggers can include:

  • Alcohol – some people find a headache can be brought on within an hour of drinking alcohol.
  • Getting too hot – such as after exercising in a warm room or having a hot bath.
  • Strong smells – such as perfumes, solvents or petrol

How is cluster headache diagnosed?

There is no test to diagnose cluster headache so your doctor will ask questions about your symptoms and the timing of them. For that reason it would help to keep an account of your symptoms using a headache diary. You may have tests done to rule out other causes of your headaches. You may also be referred to a specialist.

What are the treatment options for cluster headache?

Some of the treatment options can provide immediate relief when you are having a cluster headache. These are used just while you have the symptoms. Other treatments help to stop a cluster of headaches from starting.

  • Immediate relief: high flow oxygen therapy is considered to be safe and effective for stopping a cluster headache from getting worse. If you do not respond to high flow oxygen, another option is subcutaneous (under the skin) sumatriptan injections. Oral (by mouth) triptans usually do not work for cluster headache.
  • Preventive medications: You may need to go on preventive medications for the duration of the cluster bout. Then these medications can be weaned off when you are out of the cluster bout. Common preventive medicines used are verapamil, a short course of oral steroids, and topiramate.
  • Preventive treatment: A greater occipital nerve block may be done. This is where a pain-killer and steroid mixture is injected into the scalp at the base of the nerve. Some people find this can relieve the pain for up to several months.

How can I care for myself if I have cluster headache?

As well as taking any medicine you have been prescribed, you can avoid the things that you know trigger a cluster headache for you (see above). 

Otherwise you may find that these things help:

  • Keeping a regular sleep pattern.
  • Avoiding alcohol.
  • Stopping smoking.
  • Exercising every day.

Learn more

Headache Ministry of Health, NZ
Migraine and headache topics American Migraine Foundation, US


  1. Diagnosing and managing headache in adult in primary care BPAC, NZ, 2017
  2. Cluster headaches Patient Info, UK, 2018
  3. Headache in primary care BPAC, NZ, 2007
  4. Occipital nerve block Healthline, US, 2019
Dr Pyari Bose is a neurologist with special interest in headache disorders. He did headache research at King's College London, looking into the postdrome (recovery) phase of migraine using functional brain imaging.
Credits: Health Navigator Editorial Team . Reviewed By: Dr Pyari Bose, Consultant Neurologist, Auckland City Hospital Last reviewed: 01 Feb 2022