Headaches are exceedingly common, with half the population having experienced at least one headache within the past year. Tension type headache and migraine have been ranked as the second and third most common diseases in the world, with only dental caries affecting more people; TTH has an estimated global prevalence of 20.1 per cent and migraine 14.7 per cent.2,3

In some populations, episodic TTH (occurring on fewer than 15 days a month) can be experienced by as many as 70 per cent of people, while chronic TTH, occurring on more than 15 days a month, affects 1-3 per cent of adults.2

Around 23 per cent of UK adults experience migraine with about 190,000 migraine attacks each day. More than three quarters of migraineurs experience a migraine attack each month, with more than half having severe impairment during an attack. Three times as many women experience migraine compared to men.4,5,6

MOH is experienced by 1-2 per cent of the population globally, being highest among women in the 40-45 age group who have had a previous history of HHT and/or migraine.7

Cluster headaches, are less common but severe, affecting anywhere between 0.003 per cent to 0.4 per cent of adults. Men are more likely than women to experience them.8