People who get them find they have frequent headaches for weeks or months, then none for a long time. In a few people, the headaches come on continuously. They happen more in the night than during the day, and often at the same time each night. They are very painful.

The headaches occur on one side of the face, often around or behind the eye. They can last anywhere between 15 minutes and three hours. They can happen as often as 8 times in one day, or once every couple of days. Many people also have, on the same side of the face:

• a red and weepy eye
• a drooping or swollen eyelid
• a runny or blocked nose
• sweaty skin.

They might also feel restless or agitated.

Causes

Nobody knows what causes cluster headaches.

Cluster headaches sometimes run in families. People who get them are more likely to smoke heavily, drink heavily, drink a lot of caffeine and feel a lot of stress, but they can happen to anybody.

Diagnosis

Your doctor will talk to you and examine you. There is no specific test for cluster headache, but your doctor may do tests to rule out other conditions.

Treatments

Treatment and prevention of cluster headaches can be difficult. The usual painkillers often don’t work.

There are a range of medicines that can help prevent a cluster starting. Talk to your doctor about these.

If you are in the middle of a cluster, you can reduce your chances of having a headache by getting plenty of sleep, and sleeping at the same time each night, and also by avoiding alcohol completely. You should also try to get regular sleep, avoid stress or strenuous physical activity, and avoid a high altitude.

If you get a cluster headache, then you can try:

• medicines – talk to your doctor
• oxygen through a mask
• a nasal spray of local anaesthetic.

Talk to your doctor about these.