What criteria should I use to diagnose migraine in a patient presenting with headache?

To diagnose migraine in a patient presenting with headache, use the following criteria based on headache features:

• Pain location: unilateral or bilateral.
• Pain quality: pulsating (throbbing or banging in young people aged 12 to 17 years).
• Pain intensity: moderate or severe.
• Effect on activities: headache is aggravated by, or causes avoidance of, routine activities of daily living.
• Associated symptoms: unusual sensitivity to light and/or sound, nausea and/or vomiting.
• Duration of headache: 4 to 72 hours in adults, 1 to 72 hours in young people aged 12 to 17 years.

Additionally, consider the presence of aura, which involves fully reversible neurological symptoms developing gradually over at least 5 minutes and lasting 5 to 60 minutes. Typical aura symptoms include visual disturbances (flickering lights, spots, lines, or partial loss of vision), sensory symptoms (numbness or pins and needles), and/or speech disturbance.

Diagnose migraine with aura if these aura symptoms are present with or without headache and meet the above criteria.

Use a headache diary for at least 8 weeks to record frequency, duration, severity, associated symptoms, medications taken, possible triggers, and relationship to menstruation to aid diagnosis.

Exclude secondary causes of headache by assessing for red flags such as sudden onset, neurological deficits, fever, or changes in headache characteristics.

Chronic migraine is diagnosed if headaches occur on 15 or more days per month for more than 3 months, with at least 8 days having features of migraine.

These criteria are based on the NICE guideline "Headaches in over 12s: diagnosis and management" and related clinical guidance.