Episodic cluster headaches are the most common
type of cluster headaches. People with episodic cluster headaches have cluster
periods of 1 to 3 months when they are prone to having headaches. The cluster
periods are followed by headache-free periods (remissions) of 6 months or more.
About 90 out of 100 people who have cluster headaches have episodic cluster
Chronic cluster headaches are
those that occur during a period of at least 12 months without a headache-free
period (remission) or when remissions last less than one month.2 About 10 out of 100 people who have cluster headaches have chronic