Cluster headaches are excruciating attacks of pain in one side of the head, often felt around the eye.
They’re estimated to affect around 1 in 500-1,000 people. Anyone of any age can be affected, but they’re more common in men and tend to develop in people over the age of 20.
It’s not clear exactly what causes cluster headaches, but they’ve been linked to activity in part of the brain called the hypothalamus. People who smoke seem to be at a higher risk. Some cases also appear to run in families, which suggests there may be a genetic link.
For most people, cluster headaches occur in recurrent “bouts” over several weeks (typically 4-12 weeks) followed by headache-free periods (remission) that often last for months, or sometimes years.
Cluster headache bouts may occur every year over many years and may be lifelong. In general, they become less frequent over time. Treatment is available to control them.