What Actually Happens in Your Brain During a Migraine
By Dr. Brenna Erickson, DC
READ TIME: 6 MINUTES
Dr. Rowan just wrote a fabulous piece about chronic pain in the body through the lens of Traditional Chinese Medicine's "wind" pattern — the sense that this condition arrives suddenly, moves, and shifts unpredictably. Here's the same experience from a different angle: what's actually happening in the brain during a migraine attack, mechanically, moment by moment.
If you have ever had a migraine, you know the feeling before you have a name for it. Maybe it's the third yawn in ten minutes that has nothing to do with being tired. Maybe it's a sudden, specific craving, or a vague sense that something's coming, hours before any pain arrives. Long before you'd call it a migraine, your nervous system already knows what is happening.
Migraine affects roughly 1 in 7 people worldwide and is the second-leading cause of disability on the planet. And that’s just the group people people that know what they have is Migraine.
The definition of migraine seems almost purposefully vague. “A migraine is a headache that can cause intense throbbing pain or a pulsing feeling, usually on one side of the head. It often happens with nausea, vomiting, and extreme sensitivity to light and sound. Migraine attacks can last for hours to days, and the pain can be so bad that it interferes with your daily activities.
For some people, a warning symptom known as an aura occurs before or with a migraine. An aura can include visual changes, such as flashes of light or blind spots. The aura also can cause tingling on one side of the face or in an arm or leg and trouble speaking.
Medicines can help prevent some migraines and make them less painful. Combining medicines with self-help remedies and lifestyle changes also might help.” from the Mayo clinic.
But Migraine is a spectrum disorder, and one person’s experience doesn’t map cleanly onto another person’s.
The Real Mechanism: A Resource Allocation Problem
The migraine definition above is from the perspective of what some might experience during a migraine attack, but the list of symptoms aren’t definitive or even all encompassing. And it completely fails to explain the mechanism behind migraine, the risk factors around it, or even what to do with a diagnosis.
The most accurate way to understand what's happening draws on an idea many people with chronic conditions already know well: spoon theory. The concept, first described by writer Christine Miserandino, imagines each day starting with a limited number of "spoons" — units of energy and capacity. Every task, every stressor, every poor night of sleep costs a spoon. Most days, you have enough. Some days, you don't.
Picture a Tuesday: you slept five hours because of a late night, skipped lunch, had to have a hard conversation, and your shoulders have been up by your ears since 9am. Each of those cost a spoon. None of them, alone, would do much. But by 3pm, you're out of clean spoons — and that's when the migraine storm starts rolling in.
Stress, specifically, is reported as a trigger by nearly 70% of people with migraine, according to the American Migraine Foundation. But that statistic can mislead if you stop there — it's not that stress alone causes an attack. It's that stress costs a spoon like everything else does, and it's often the last one spent, not the sole cause. This is why the same "trigger" doesn't cause a migraine every time it shows up, and why chasing a single cause rarely tells the full story.
Cortical Spreading Depression: the thunderstorm that rolls in
For the roughly 25-30% of people with migraine who experience aura, a specific, well-documented mechanism called cortical spreading depression explains that phase. A slow wave of electrical activity moves across the surface of the brain — about 2 to 3 mm a minute — causing temporary, localized disruption in whatever functional brain region it crosses: shimmering lines if it crosses the visual cortex, difficulty finding words if it crosses a language area, tingling if it crosses a sensory region.
This is why aura seems to "travel" from one symptom to the next — it isn't several separate symptoms that happen to occur together. It's one electrical wave, moving across your brain, and the specific symptoms depend on exactly which part of the brain it happens to.
Since the majority of people with migraine never experience aura at all, this mechanism explains an important piece of the picture — not the whole disease process.
Where the Pain Comes From
Whether or not aura is part of the picture, the headache phase itself traces back to the trigeminal nerve, the major sensory nerve serving the face and head. When activated, it releases inflammatory neuropeptides — including one called CGRP (calcitonin gene related peptide) — directly into the blood vessels surrounding the brain. Researchers have described CGRP as "essential for migraine pathophysiology," and it's the mechanism an entire modern class of preventive medications was built around.
Those blood vessels become inflamed and dilated once CGRP is released, and that inflammation is where the pain itself originates — part of why migraine pain so often has a throbbing, pulsing quality that tracks with blood flow rather than staying constant.
Even this piece of the mechanism isn't universal: recent research phenotyping actual attacks found that about 73% are driven primarily by the CGRP pathway, while the remaining attacks appear to run through a different mechanism entirely. Even at the level of the blood vessels themselves, migraine isn't one single process.
Migraine Doesn't Look the Same for Everyone
The Resource Allocation limitation doesn't produce the same experience in every person. ICHD-3, the diagnostic reference clinicians use, formally recognizes more than 20 distinct symptoms spread across migraine's phases — 6 different types of aura alone (if someone even experiences aura), from visual disturbances to temporary motor weakness, plus separate sets of prodrome and postdrome symptoms, and even more subtype-specific presentations like the vertigo (spinning sensation) of vestibular migraine or the abdominal pain seen mainly in children.
Cortical spreading depression, for instance, doesn't always travel across the same part of the brain — it depends on which region happens to be in its path, which is why one person's aura is visual and another's is a language disruption. The trigeminal-CGRP pathway that produces pain doesn't always dominate either, as the 73% figure above shows. And the nervous system's broader dysregulation can involve the vestibular system, the gut, or neither, depending on how someone's particular wiring responds under load.
None of this is random variation — it's the same underlying mechanism, expressing itself through whichever systems are most vulnerable in a given person. No single symptom is required for diagnosis, and most people experience only a fraction of the full list. If you want the fuller picture of how differently migraine can present, an article from Migraine Whisperer called “Naming It” covers the full spectrum in depth.
Why Your Migraine Isn’t Random
Migraine does have a real genetic component. Twin studies consistently estimate its heritability at somewhere between 40 -50% — meaning genetics account for roughly half of why some people develop this and others don't. The other half is everything else: sleep, stress, hormones, blood sugar, and overall nervous system health, all costing or protecting the same number of spoons described above.
This is often described as your Migraine Threshold — your nervous system's capacity to absorb everyday demands before it tips into an attack. Genetics can set where that threshold generally sits. Daily life determines how many spoons you're running on at any given moment.
This reframes the whole mainstream migraine management approach. Instead of identifying and permanently avoiding a single trigger, the more accurate goal is raising your overall capacity to absorb everyday demands, so the same stack of stressors has less power over you, making you more resilient.
Where to Go From Here
If any of this resonated, I have a few places for you to keep exploring:
What Is Migraine— the fuller picture of migraine's phases, subtypes, and how a real diagnosis works from my Migraine Whisperer site.
The ICHD-3 (International Classification of Headache Disorders) — the actual diagnostic reference clinicians use, publicly available at ichd-3.org, if you want to go straight to the source
What Migraine Care Can Actually Look Like: The Integrative Approach at Stockheart: you're probably wondering: what does addressing this look like? What would it mean to come to Stockheart? What happens, concretely, and is it something that could work for my life?
If you're navigating migraine in the Twin Cities, our team brings over 60 combined years of clinical experience across chiropractic, traditional chinese medicine, functional medicine, and integrative care. Book a consult with our team and let's map out what's actually driving your pattern, together.
At Stockheart Whole Health, we believe your symptoms are clues, not noise — and that living well with a chronic condition means building a life that fits the body you have, not the one you're told you should have. Your home for heart-centered, whole-person healing.
