Synopsis
Diagnose migraine positively from its episodic phenotype, distinguish typical aura from vascular or epileptic mimics, and recognise when a changing pattern needs secondary-headache investigation.
- Migraine is a positive clinical diagnosis: recurrent attacks commonly last 4–72 hours and combine moderate or severe headache with nausea or sensitivity to light and sound.
- The pain may be unilateral or bilateral, often pulsating and aggravated by routine activity, but no single descriptor is required when the overall pattern is characteristic.
- Typical aura is fully reversible visual, sensory or speech disturbance that develops gradually over at least 5 minutes and usually lasts 5–60 minutes for each symptom.
- Positive spreading phenomena, such as scintillation or marching paraesthesia, favour aura; abrupt maximal negative loss, persistent deficit or simultaneous symptoms raise concern for TIA or another cause.
- Aura may precede, accompany or occur without headache, and an individual can have attacks both with and without aura across their lifetime.
- Use a headache diary for at least 8 weeks when diagnosis or burden is uncertain, recording frequency, duration, severity, associated symptoms, medicines, triggers and menstruation.
- Do not image a stable typical migraine solely for reassurance when examination is normal and there are no secondary features; explain the positive diagnosis and safety net instead.
- Offer contraception and vascular-risk counselling where relevant: current UKMEC classifies combined hormonal contraception as category 4 in migraine with aura, so it should not be used while safer contraceptive options are discussed.
- Diagnose chronic migraine when headache occurs on at least 15 days per month for more than 3 months with migraine features on at least 8 days, while also assessing medication overuse.
Key red flags
Motor weakness, diplopia, monocular visual symptoms, reduced consciousness or impaired balance requires further assessment because it falls outside straightforward typical-aura diagnosis.
Sudden fixed deficit, first or worst abrupt pain, seizure features, fever, papilloedema or progressive personality change should move the clinician away from uncomplicated migraine.
Investigation priorities
Make a positive migraine diagnosis and identify a meaningful change or secondary-headache feature.
Management branches
A person reports episodic headache with or without transient neurological symptoms.
- Establish duration, frequency, onset speed, pain behaviour, nausea, sensory sensitivity, disability and complete recovery, then compare every feature with previous attacks.
- For neurological symptoms record whether phenomena were positive or negative, gradual or abrupt, sequential or simultaneous, and fully reversible within the expected duration.
- Screen for systemic, vascular, pressure, pregnancy and examination red flags before assigning migraine with or without aura.
- Explain the positive diagnosis, begin a diary when useful and agree separate plans for acute treatment, prevention threshold and urgent reassessment.