Four phases (not all present every attack): premonitory (hours-days before — mood change, food cravings, neck stiffness, yawning, fatigue), aura (if present, 5-60 min, fully reversible), headache (4-72 hours untreated), postdrome (fatigue, mood change, cognitive fogginess)
Headache characteristics: unilateral (can be bilateral, especially in children), pulsating/throbbing, moderate-severe intensity, aggravated by routine physical activity
Associated features: nausea ± vomiting, photophobia, phonophobia (patient seeks dark, quiet environment)
Aura (if present): visual most common; scintillating scotoma, zigzag fortification spectra, expanding/migrating over 5-20 minutes, followed by or overlapping with headache onset
Triggers: stress (and post-stress relaxation), hormonal changes (menstruation, oral contraceptives), sleep disruption, fasting/skipped meals, specific foods (variable, individual; chocolate, cheese, alcohol/red wine, caffeine withdrawal), dehydration, weather changes, sensory stimuli (bright/flickering lights, strong odors)
Diagnostic criteria (ICHD-3, migraine without aura): ≥5 attacks fulfilling: duration 4-72 hours (untreated), ≥2 of (unilateral, pulsating, moderate-severe intensity, aggravation by activity), and ≥1 of (nausea/vomiting, photophobia+phonophobia)
Red flags ("SNOOP" mnemonic: warrant urgent investigation to exclude secondary headache): Systemic symptoms/illness (fever, weight loss, malignancy history), Neurological signs/symptoms (focal deficit, altered consciousness, papilledema), Onset sudden/thunderclap (subarachnoid hemorrhage until proven otherwise), Older age (>50, new headache — giant cell arteritis, malignancy), Pattern change (progressive, positional, precipitated by cough/exertion/Valsalva, or first/worst headache)