The Landmark study, from 15 countries, reported that 94% of patients attending a GP with episodic disabling headache had migraine. Generally, an untreated migraine headache is moderate to severe and lasts for more than four hours. It is often pulsating, but patients may describe a feeling of ‘expanding pressure’ within the head. Most sufferers experience nausea although fewer patients actually vomit. Acute treatment should be taken as soon as a migraine headache starts to develop as later in the attack central sensitisation occurs and treatments become less effective.