Key Takeaways
What Is a Migraine, Really?
Most people have heard migraines described as "really bad headaches," but that framing undersells what's actually happening. A migraine is a complex neurological disorder — one that affects roughly 1 in 7 adults worldwide and involves dramatic, coordinated changes in brain activity, blood flow, and sensory processing.
Pain, when it occurs, is just one chapter in a longer story. Many people with migraines experience warning signs hours before any head pain arrives and symptoms that linger long after the worst of it has passed. Understanding the full scope of a migraine attack helps explain why it can be so disabling — and why managing it effectively often requires more than over-the-counter pain relief.
1 in 7
Adults affected by migraines worldwide
Migraine is consistently ranked among the top causes of disability globally, according to the Global Burden of Disease Study.
4–72 hrs
Typical duration of a migraine headache phase
Per the International Headache Society's diagnostic criteria for migraine without aura.
~30%
People with migraines who experience aura
Estimates from epidemiological research suggest roughly 25–30% of migraine sufferers report aura symptoms.
The Four Phases of a Migraine Attack
Neurologists typically divide a migraine attack into four phases, though not everyone experiences all of them.
Phase 1: Prodrome
Up to 48 hours before head pain begins, subtle shifts signal that an attack is on its way. These prodrome ("pre-headache") symptoms vary widely but commonly include unusual fatigue, frequent yawning, neck stiffness, food cravings, heightened sensitivity to light or sound, and mood changes — either irritability or an unexplained feeling of elation. Many people learn to recognize these as personal warning signs over time.
Phase 2: Aura
Roughly 25–30% of people with migraines experience aura — a set of fully reversible neurological symptoms that typically last 20 to 60 minutes. Visual aura is most common: shimmering zigzag lines, blind spots, or flashing lights that move across the visual field. Some people experience sensory aura (tingling that spreads across the face or hand) or, rarely, temporary speech difficulty. Aura is not always followed by pain.
Phase 3: Headache
The headache phase can last 4 to 72 hours. The pain is classically described as a pulsing or throbbing sensation, often on one side of the head, and is typically worsened by routine physical activity. Nausea, vomiting, and extreme sensitivity to light (photophobia) and sound (phonophobia) are hallmarks. Many people find even low light unbearable and prefer to rest in a dark, quiet room.
Phase 4: Postdrome
After the headache resolves, a "migraine hangover" phase — called postdrome — often follows for up to 24 hours. Brain fog, fatigue, difficulty concentrating, and a dull residual head discomfort are typical. Sudden movement may briefly bring back the throbbing sensation.
Track Your Prodrome Symptoms
Start logging early warning signs like unusual yawning, food cravings, or neck stiffness in a dedicated headache diary or app. Over several weeks, patterns often emerge that help you anticipate an attack — and take early action before head pain fully develops.
What's Happening in the Brain
Migraine research has advanced considerably, and scientists now have a clearer picture of the neurology behind each phase.
Cortical Spreading Depression
Aura is explained by a phenomenon called cortical spreading depression (CSD) — a slow wave of electrical hyperactivity followed by suppressed activity that moves across the brain's outer layer (the cortex) at roughly 3–5 mm per minute. As this wave passes over the visual cortex, it produces the characteristic zigzag or flickering lights. CSD appears to also trigger the cascade of events that eventually leads to head pain.
Trigeminal Nerve Activation
The headache pain itself is largely driven by the trigeminal nerve, the brain's main sensory highway for the face and head. During the headache phase, trigeminal nerve fibers activate and release inflammatory signaling molecules around blood vessels in the brain's meninges (the protective membranes). This produces the throbbing, pressure-like pain most people associate with migraines.
The Role of CGRP
A protein called calcitonin gene-related peptide (CGRP) plays a central role in migraine pain. Released during trigeminal activation, CGRP dilates blood vessels and promotes pain signaling. It's also the target of a newer class of migraine-specific medications — knowledge that has significantly changed treatment options in recent years.
“Migraine is not just a headache disorder — it is a brain disorder, and the pain is just one of its many manifestations. Understanding the neurobiology opens the door to much better treatment.”
— Peter Goadsby, Professor of Neurology, widely published migraine researcher
Common and Overlooked Triggers
A trigger is anything that raises the likelihood of an attack in a susceptible person. Importantly, triggers don't cause migraines — they push the brain past a threshold it was already approaching. That's why the same glass of red wine triggers an attack one week but not the next: your overall "threshold" shifts based on sleep, stress, hydration, and hormonal factors all working together.
Well-Known Triggers
- Hormonal fluctuations: Many women find attacks cluster around menstruation, when estrogen levels drop sharply.
- Sleep disruption: Both too little and too much sleep are reported triggers.
- Stress and stress let-down: The "weekend migraine" often strikes when tension finally releases.
- Dehydration and skipped meals: Irregular eating and low fluid intake are among the most consistently reported triggers.
- Sensory stimuli: Bright or flickering lights, strong perfumes, and loud noise.
Frequently Overlooked Triggers
- Weather changes: Shifts in barometric pressure are a real and validated trigger for many people.
- Caffeine — in both directions: Regular overconsumption and sudden withdrawal both raise risk.
- Posture and neck tension: Long hours at a screen in poor posture can build musculoskeletal tension that contributes to an attack.
Think of your trigger threshold like a bucket: individual triggers add water, but it overflows only when the bucket is nearly full. Address multiple small factors — sleep, hydration, stress — and single triggers often lose their power.
Research shows migraine susceptibility is cumulative, meaning the interaction of multiple sub-threshold factors, rather than any single trigger, often precipitates an attack.
If you suspect a dietary trigger, avoid eliminating multiple foods at once. Remove one candidate at a time for two to four weeks to clearly identify whether that specific food is actually contributing.
Broad elimination diets make it difficult to isolate true triggers and can unnecessarily restrict nutrition; a systematic approach yields more reliable information.
When to Talk to a Doctor
Migraines are underdiagnosed and undertreated — surveys consistently find that many people who meet the clinical criteria have never received a formal diagnosis. If headaches are interfering with your daily life, affecting work, or requiring you to miss activities regularly, speaking with a healthcare provider is a practical and worthwhile step.
Seek Immediate Care for These Symptoms
A sudden, severe headache that comes on in seconds (often described as a "thunderclap"), headache accompanied by fever, stiff neck, confusion, vision loss, weakness, or difficulty speaking warrants emergency evaluation. These can be signs of a serious condition unrelated to migraine. Do not attempt to self-diagnose — seek care promptly.
A doctor can confirm whether your headaches fit a migraine pattern, rule out other causes, and help you build a management plan. This typically involves identifying your personal triggers (a headache diary is an evidence-supported starting tool), discussing acute medications for when attacks do occur, and, if attacks are frequent, exploring preventive approaches.
Keep track of headache frequency, duration, associated symptoms, and potential triggers in a diary or app between appointments — this information is genuinely useful to a clinician and shortens the path to an effective plan.
This article is for general health information purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about symptoms or medical concerns.
