What Is a Migraine?
A migraine is a neurological disorder characterised by recurrent attacks of moderate-to-severe, often one-sided, throbbing headache lasting 4–72 hours. It is accompanied by nausea, vomiting, and extreme sensitivity to light (photophobia) and sound (phonophobia). Unlike ordinary tension headaches, migraines are disabling — attacks prevent normal activity and often require lying down in a dark, quiet room.
Types of Migraine
- Migraine without aura (common migraine) — accounts for 75% of cases; no preceding neurological symptoms
- Migraine with aura (classic migraine) — aura is a transient neurological phenomenon lasting 20–60 minutes before or during the headache: visual disturbances (zigzag lines, blind spots, flashing lights), sensory changes (tingling), or speech difficulties. Aura represents cortical spreading depression — a wave of electrical activity moving across the brain.
- Chronic migraine — ≥15 headache days per month for >3 months, with ≥8 meeting migraine criteria
- Vestibular migraine — prominent vertigo and dizziness with or without headache
Common Triggers
Triggers lower the threshold for attacks — they don't directly cause migraine, which requires an underlying genetic predisposition. Common triggers include:
- Hormonal changes (falling oestrogen around menstruation)
- Sleep disruption (too much or too little)
- Skipping meals or dehydration
- Stress (or the "let-down" after stress ends)
- Alcohol (especially red wine and beer)
- Bright or flickering lights, strong smells
- Caffeine (withdrawal can trigger an attack)
- Weather changes (barometric pressure drops)
Acute (Abortive) Treatment
Triptans (sumatriptan, rizatriptan, eletriptan) are the first-line specific treatment for moderate-to-severe attacks. They are serotonin (5-HT₁B/1D) agonists that constrict dilated cranial vessels and block pain signal transmission. Take as early as possible during an attack — they are far less effective once the headache is fully established. They are contraindicated in patients with cardiovascular disease.
Gepants (ubrogepant, rimegepant) are CGRP receptor antagonists — a newer acute treatment that does not cause vasoconstriction, making them safe for cardiovascular patients. Rimegepant also has preventive properties when taken every other day.
NSAIDs (ibuprofen, naproxen, aspirin) with or without caffeine are effective for mild-to-moderate attacks. Caution: using any acute headache medication more than 10–15 days per month can cause medication overuse headache (rebound headache).
Preventive Treatment
Prevention is recommended when attacks occur ≥4 days/month or are severe and disabling. Traditional options include beta-blockers (propranolol, metoprolol), tricyclics (amitriptyline), anticonvulsants (topiramate, valproate), and calcium channel blockers (flunarizine).
The biggest advance in migraine prevention in decades has been anti-CGRP monoclonal antibodies: erenumab (Aimovig), fremanezumab (Ajovy), galcanezumab (Emgality), and eptinezumab (Vyepti). Monthly or quarterly injections reduce migraine days by 50% or more in ~50% of patients. They work specifically by blocking CGRP — a neuropeptide central to migraine pathophysiology — with minimal side effects.
OnabotulinumtoxinA (Botox) is approved for chronic migraine: 31 injections around the head and neck every 12 weeks, reducing headache days by ~9 per month.