Unlike migraine, a cluster headache usually has a fast onset with no advance warning, and typically lasts from 15 minutes to three hours. The pain can be so intense that it is sometimes known as ‘suicide headache’ with the person becoming restless or agitated (unlike in migraine) and trying to relieve pain by applying pressure.8,13

The trigeminal nervous system is involved, and autonomic symptoms will be present. This can include excess tears, eye redness or irritation, nasal symptoms, blocked ears, throat swelling and flushing or sweating on the face.

The name cluster headache derives from bouts of headaches coming on for perhaps six to 12 weeks at a time before a remission of months or even years. This episodic cluster headache type occurs in around 80 per cent of patients, while the remaining 20 per cent experience chronic cluster headache with no pain-free remission periods.8,15

During a bout, the headaches may happen typically from one to eight times a day. A circadian rhythm is common, with headaches appearing at the same time each day. Some people find bouts are increasingly likely at similar times of the year, such as the equinoxes.8,13

Triggers can include alcohol, strong smells such as solvents, and nitrates in foods such as cured meats.8