Migraine

**Definition:** A primary headache disorder, in most cases episodic. Disabling attacks lasting 4-72 hours are characterised by moderate or severe headache, usually accompanied by nausea, vomiting and/or photophobia and phonophobia, and sometimes preceded by a short-lasting aura of unilateral fully-reversible visual, sensory or other central nervous system symptoms. In a small minority of cases headache, but not necessarily the associated symptoms, becomes very frequent, with loss of episodicity.

**Exclusions:** - Headache, not elsewhere classified