Cluster headaches have been officially recognized as a syndrome for more than 100 years.
It's much less common than migraine and affects around 69 people out of every 1000,000.
Men seem to get it more often than women, in a ratio of 6 to 1.
Most people begin having these types of headache around the age of 30 but it can start at any age between 20 and 50.
In rare cases, it has been known to start as early as 10 years old and as late as 80! Women who do have cluster headaches are more likely to start them after the age of 50.
They don't seem linked to the menstrual cycle but do appear to stop during pregnancy.
Why are they called cluster headaches? This is because the attacks are 'clustered' into bouts.
A bout of attacks usually lasts from between 4 and 8 weeks and then stop, in 90% of sufferers.
In 80% of cases, the pain-free time between bouts will be anything from a month to 2 years.
60% will have a respite for 6 months - 2 years.
Some bouts may only last a few days.
Some have been known to go on for as long as four months.
About 10% of sufferers will become 'chronic' where the bouts may go on for 4 - 5 years.
What symptoms make up the cluster headache syndrome? If you can answer yes to many of these categories, then you may be suffering from cluster headache syndrome.

• You are male, aged 20-50
• Headache is one sided
• Headache is in your eye and socket
• The pain is sudden and explosive
• It often wakes you from sleep at night
• You have many headaches for weeks (the cluster 'bout') and then none from months
• You get a stuffed up nose with the headache
• Your forehead sweats
• Your eyes run
• Your face sometimes droops during a headache
• You are more sensitive to alcohol during a headache cycle

What sort of pain is it? The characteristic pain of cluster headache is sudden and reaches a peak within 2-15 minutes.
It usually starts in or above the eye.
Sometimes it starts in the face, ear or neck.
It is always on one side only.
15% of sufferers say that it will switch sides from one attack to another.
It is even less common for it to switch sides during an attack.
It's often described as excruciating.
It feels deep, non-changing and like something has exploded in the head.
10-20% of sufferers describe it as an ice pick stabbing them in the eye socket several times.
This type of feeling usually means that the attack is nearly over.
How long does it last? In 75% of cluster cases, attacks can last from 30 minutes to 2 hours.
This averages out at 45 minutes for an attack - but it is a long time to be in excruciating pain.
Mild attacks may only last for 10 minutes but severe ones can go on for many hours.
How often do people have them? It can vary from as many as 6 in 24 hours - to one a week.
The average is one or two a day.
Periodicity This is an interesting feature of cluster headaches.
In around 85% of sufferers, attacks seem to happen at the same time each day, for as long as the bout continues.
Many people also have random attacks throughout the day, on top of this constantly recurring one.
How strange! What are the most common times?

• 75% of attacks happen between 9pm and 10am
• 1am - 2am
• 1 - 3 pm
• At 9 pm
• Around 50% of sufferers are woken from sleep within 2 hours of falling asleep.
  

What treatment is there? As attacks come on so quickly and often last for a short time, medication in the form of inhalers is best.
The usual treatment is with an ergotamine inhaler, which can bring relief within 5 minutes and is effective for about 80% of sufferers.
Many people are also now trying oxygen therapy which seems to work very well.
Contact your doctor to work out a treatment for you.