What are cluster headaches?

Cluster headaches are a rare but very painful type of headache in which headaches occur in a group, or cluster. Treatments can shorten an attack and make it less severe.

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

There are 2 main types of cluster headache:

• Episodic: These occur regularly for between one week and a year followed by a headache-free period (remission) of at least 14 days. These are the most common type of cluster headache.
• Chronic: These occur regularly for longer than a year without remission or with remissions that last less than 14 days.

When should I call an ambulance?

Most headaches are not serious. But headaches can also be a sign of a serious illness, such as a stroke or meningitis.

Call triple zero (000) and ask for an ambulance, or go to the hospital emergency department if you have a headache and:

• it comes on suddenly, is very severe, or has made you lose consciousness
• you have suffered a head injury
• you have trouble seeing, walking or speaking
• your arms or legs feel numb
• you have nausea or vomiting (if not clearly related to a flu or hangover)
• you have a high fever (above 38° C)
• you are sensitive to light and have a new rash

What symptoms are related to cluster headaches?

The pain of cluster headaches can be very severe — much worse than a migraine. The headaches occur on one side of the face, often around or behind the eye. They can last from between 15 minutes and 3 hours. They can happen as often as 8 times in one day, or once every couple of days. Many people also experience other symptoms on the same side of the face such as:

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

They might also feel restless or agitated.

What causes cluster headaches?

Nobody knows what causes cluster headaches and they can happen to anybody. However, people who smoke, drink heavily or drink a lot of caffeine may have a greater risk. Cluster headaches sometimes run in families. Men are far more likely than women to get cluster headaches.

Unlike migraine and tension headaches, cluster headaches aren’t linked with triggers such as food or hormones. However, once a cluster starts, substances that dilate the blood vessels, such as alcohol, can trigger a splitting headache. Other triggers include medications that dilate blood vessels such as nitroglycerin (a medication for heart disease).

When should I see my doctor?

If you think you have cluster headache, it’s important to see your doctor so they can rule out other conditions, find the best treatment or refer you to a specialist. Treating cluster headache can be complex so it may be best done by a neurologist, a doctor who specialises in this and other areas.

Go to the hospital emergency department if you have any headache that:

• is an abrupt and severe headache, unlike you’ve ever had before
• comes with a fever, nausea or vomiting, a stiff neck, mental confusion, seizures, numbness, or speaking difficulties
• occurs after a head injury, even if it's a minor fall or bump, especially if it worsens
• worsens over days and changes in pattern

How are cluster headaches diagnosed?

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.

How are cluster headaches treated?

The main treatment for cluster headache is medication. There are medications for acute treatment which work quickly to treat the headache when it starts. Different medications may be used to help prevent a cluster starting. Your doctor will talk to you about which medications you need.

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

Can cluster headaches be prevented?

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
• avoiding alcohol
• not smoking
• avoiding strenuous physical activity and high altitude

Talk to your doctor about which preventative steps you can take.