Cluster headaches

Produced by Louise Abbott, Bupa Health Information Team, December 2011.

This factsheet is for people who have cluster headaches, or who would like information about them.

Cluster headaches are severe headaches that only occur on one side of your head, usually around or behind the eye or temple (the flat part of your head at the side of your forehead). They are called cluster headaches because they occur in clusters (bouts) up to eight times a day over many weeks or months.

About cluster headaches

About one to two people in 1,000 get cluster headaches in the UK, making them a rare type of headache. Cluster headaches are more common in men; between three and seven times more men have cluster headaches than women.

Cluster headaches tend to begin in your 30s or 40s, but once you start having them you’re likely to have bouts for the rest of your life.

Symptoms of cluster headaches

If you have cluster headaches, you will have a very severe pain on one side of your head. This pain is usually felt around or behind your eye or around your temple. You will probably have other symptoms on the same side as the pain, such as: 

• reddening or watering of your eye
• the pupil in your eye shrinking to a small size
• a drooping eyelid (ptosis)
• a swollen eyelid
• a runny or congested nose
• facial or forehead sweating

You may also have symptoms similar to those of a migraine, although this is uncommon. These include:

• sensitivity to light
• sensitivity to noise
• feeling sick or vomiting

These symptoms may be caused by problems other than cluster headaches. If you have any of these symptoms, see your GP.

A cluster headache usually lasts for about an hour, although if it’s very severe it can last up to three hours. You’re likely to feel restless and you may want to pace about. You will probably find that cluster headaches begin around the same time each day and bouts of headaches happen around the same time each year. Often, cluster headaches will wake you up within a couple of hours of going to sleep. After about six to 12 weeks of having a regular pattern of cluster headaches, you will probably have a remission period of a month or more when you have no headaches. This is known as episodic cluster headaches.

You may have a continuous background headache between the more severe attacks of pain. Up to two in 10 people with cluster headaches have no remission periods over the course of a year. This is known as chronic cluster headaches.

Causes of cluster headaches

The cause of cluster headaches isn’t fully understood at present. They may run in families, so you’re more likely to get them if one of your close relatives does too. There is some evidence that people with cluster headaches may smoke more than people who don’t get cluster headaches, as well as drinking more alcohol and coffee. It’s not clear whether stopping smoking has a positive effect on cluster headaches.

There are some things that may trigger cluster headaches, but usually only when you’re going through a bout. In remission periods these same triggers don’t have the same effect. Triggers include drinking alcohol and being exposed to strong smells such as petrol, paint fumes, cigarette smoke and perfume. Another trigger is an increasing temperature of your surroundings. Because cluster headaches often happen after a couple of hours of sleep, daytime napping can be a trigger.

There is some evidence to suggest that the hypothalamus is involved in regulating the predictable pattern of cluster headaches. The hypothalamus is part of the brain that controls your body's daily rhythms and has an effect on mood, appetite and sleep.

For some people, a previous serious head injury can lead to cluster headaches developing, but there is a long time delay between the injury and the start of the headaches. If you have a headache immediately after a head injury that keeps getting worse, you should see your GP or seek urgent medical attention.

Diagnosis of cluster headaches

If you think you have cluster headaches, see your GP. He or she will ask you about your symptoms and examine you. Your GP may ask you about your medical history and also that of your family. He or she may take your blood pressure.

Your GP will ask you about how often the pain happens and when it occurs. Therefore, you may find it useful to keep a headache diary for a couple of weeks before visiting your GP. If you can, try to record each episode of a headache, its severity, how long it lasts, any other symptoms, whether or not you took any painkillers and anything you ate or drank beforehand. This can help to get the right diagnosis. You may also begin to see a pattern in what triggers the cluster headaches and be able to avoid these things. Cluster headaches can easily be confused with other types of headache or may be caused by another illness.

If your GP thinks you have cluster headaches, he or she may refer you to a headache specialist. This is usually a neurologist – a specialist who identifies and medically treats conditions that affect the nervous system (including the brain).

There are other headaches that may be similar to cluster headaches, so you should see your GP or seek urgent medical attention if:

• you get a sudden, severe headache unlike any you have had before
• the pain is worst when you wake up
• your headache follows shortly after a head injury

You should also see your GP or seek urgent medical attention if you have a headache accompanied by:

• a stiff neck
• a fever (high temperature) and rash
• confusion
• paralysis
• numbness
• changes to your vision
• slurred speech
• changes in your behaviour

Treatment of cluster headaches

Your GP may refer you to a neurologist for treatment. There are medicines that can help you to manage cluster headaches, although there is currently no cure. Your doctor can prescribe various treatments that all aim to reduce the severity of your cluster headaches, or even prevent them from starting. These treatments can reduce the length of each bout of headaches. The treatments used will vary depending on whether you have episodic or chronic cluster headaches.

Cluster headaches are very unlikely to get better when treated with over-the-counter painkillers such as paracetamol or ibuprofen. If you have cluster headaches, you will need a prescription for other types of medicine.

Medicines

The medicine that has been found to be most effective is sumatriptan, which you have as an injection. A nurse will show you how to give yourself the injection in your stomach or thigh. You won’t be prescribed sumatriptan injections if you’re pregnant or breastfeeding, or have cardiovascular conditions including coronary artery disease or stroke.

There are a number of side-effects that you may get with sumatriptan, including sensations of tingling, heat, heaviness, pressure or tightness in any part of your body. Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.

Another option that may be more suitable, but is slower to take effect, is a nasal spray containing zolmitriptan.

Oxygen

Many people with cluster headaches find that breathing in pure oxygen from an oxygen cylinder relieves their symptoms quickly with few side-effects. Your GP can prescribe oxygen for you if this is suggested by your neurologist. You can have oxygen treatment at home, as many times a day as you need. You will need a high flow system so that the oxygen concentration you inhale is 100 percent, as lower concentrations won’t usually help.

Prevention of cluster headaches

Self-help

If you‘re having a bout of cluster headaches, you can help yourself by avoiding any triggers you have identified. When you aren’t having a bout of cluster headaches, you will probably find that these same things don’t set off your headaches.

Medicines

There are a number of different medicines that your doctor can prescribe to help prevent cluster headaches. The most common medicines include verapamil and lithium. You may find some medicines more effective than others and you may need to try different ones to get the best result. There are side-effects to some of these medicines and your doctor will monitor you to ensure that you can take these medicines safely.

Surgery

There have been a number of small studies that show that a new technique called occipital nerve stimulation is effective for preventing chronic cluster headaches in some people. This technique involves surgically inserting a tiny device into the back of your scalp, which stimulates the greater occipital nerve that is involved in causing the headaches. This device produces a small electrical stimulation that you regulate with a remote control. This is only available in specialist centres when all other options have been found to be ineffective. More medical trials of this technique need to be carried out to find out how safe and effective it is.

If you get chronic cluster headaches and other treatments haven’t worked, you may be offered a type of brain surgery. However, this is usually only considered as a last resort because of the serious risk of complications that can occur.

Living with cluster headaches

The severity of the pain from cluster headaches can make them difficult to live with. Carefully following the treatment plan from your doctor and returning for further advice can help to keep your cluster headaches under control. Get to know your triggers and take steps to avoid these. Ask for support from your family and friends, who may be able to help with everyday tasks when your pain is particularly severe. There are also self-help groups that you can join to meet other people who have the same condition.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.