Part 3: Why Migraine Is More than Just a Vascular Disorder
For decades, migraine was taught as a vascular disorder.
The prevailing theory was simple: blood vessels constrict, then dilate, and the dilation causes pain.
It seemed to make sense. Migraine pain often throbs with each heartbeat. Nitroglycerin, which releases nitric oxide and causes vasodilation, can reliably trigger migraine attacks in susceptible individuals. Medications such as triptans produce vasoconstriction and often relieve symptoms.
Case closed.
Except...it wasn't.
Over the last twenty years, neuroscience has revealed that blood vessels are only one piece of a much larger story.
The Simple Thought Experiment
Here's an easy way to think about it.
If migraine were purely a vascular disorder, then anything that constricted blood vessels should reliably stop migraines.
But that's not reliably what we see.
Clearly, something else is happening.
The blood vessels are participating in the process—not driving it.
Why Doesn't Nitric Oxide Trigger a Migraine in Everyone?
Nitric oxide (NO) is one of the most fascinating examples.
Researchers have known for years that nitric oxide donors can trigger migraine attacks in susceptible people.
But here's the important question:
If vasodilation alone causes migraine, why doesn't nitric oxide trigger migraines in everyone?
Because the blood vessels aren't the underlying problem.
Instead, nitric oxide appears to lower the threshold of an already vulnerable nervous system.
Think of it like striking a match.
A match only starts a fire if there's dry wood waiting to burn.
Likewise, nitric oxide only triggers migraine in people whose nervous systems are already predisposed toward migraine.
The trigger isn't creating the disease.
It's exposing it.
A Brain Primed for Migraine
Modern migraine research increasingly views migraine as a disorder of altered brain excitability.
The brain becomes unusually sensitive to internal and external stimuli long before pain begins.
Once that threshold is crossed, numerous downstream events occur:
activation of the trigeminal system
release of CGRP and inflammatory neuropeptides
altered sensory processing
autonomic dysfunction
changes in cerebral blood flow
Notice where blood flow appears on that list.
It isn't necessarily the first domino.
It's one of many physiologic changes occurring during a migraine attack.
Why This Matters for Acupuncturists
This shift has profound implications for treatment.
If migraine is more than a vascular disorder, then treatment shouldn't focus solely on changing blood flow.
It should aim to reduce the brain's overall susceptibility to entering the migraine state.
That means considering factors such as:
sleep
stress physiology
autonomic regulation
hormones
inflammation
sensory processing
diet and metabolic health
cervical dysfunction
Acupuncture has the unique advantage of influencing many of these systems simultaneously, which may help explain why it continues to show benefit across a wide range of migraine populations. We still need to exercise certain cautions…
A Clinical Pearl: Believe Your Patient
One of the most valuable lessons I've learned from treating migraine patients is to listen carefully when they tell me what their nervous system can—and cannot—tolerate.
Occasionally a patient will say,
"Please don't put needles in my scalp. It gives me a migraine."
It may be easy to dismiss that comment.
After all, scalp acupuncture is widely used for headache disorders, and many patients respond beautifully to it.
But not everyone does.
In some individuals, the trigeminovascular system is already operating so close to its migraine threshold that additional sensory input—even something as seemingly therapeutic as local scalp acupuncture—may be enough to trigger an attack.
That doesn't mean scalp acupuncture is "wrong."
It means that patient is telling you something important about the current state of their nervous system.
When we begin thinking of migraine as a disorder of altered sensory gain rather than simply a headache, these experiences become much easier to understand.
The question shifts from:
"Why would acupuncture cause a migraine?"
to
"Why is this patient's nervous system interpreting even helpful sensory input as a potential threat?"
Sometimes the answer is to work with the nervous system before working directly on the head.
Distal acupuncture, autonomic regulation, addressing gut dysfunction, improving sleep, addressing hormonal or inflammatory contributors, and gradually lowering the patient's migraine threshold may all make scalp treatment more tolerable later.
In other words, don't force the protocol.
Treat the nervous system in front of you.
Looking Ahead
Understanding that migraine isn't simply a vascular disorder changes how we think about every aspect of assessment and treatment.
Rather than asking,
"How do I stop the headache?"
we begin asking,
"Why is this nervous system so easy to push into a migraine state?"
That question opens an entirely different way of thinking about migraine.
Suggested References
- Ferrari, M. D., Goadsby, P. J., Burstein, R., Kurth, T., Ayata, C., Charles, A., . . . Dodick, D. W. (2022). Migraine. Nat Rev Dis Primers, 8(1), 2. doi:10.1038/s41572-021-00328-4
- Charles A. The Pathophysiology of Migraine: Implications for Clinical Management. Lancet Neurol. 2018.
- Goadsby PJ, Holland PR, Martins-Oliveira M, et al. Pathophysiology of Migraine. Physiol Rev. 2017.
Continue Rethinking Migraine
Part 1: Migraine Is a Brain State, Not Just a Headache
Part 2: The Four Phases of Migraine—Why the Headache Is Only One Part of the Story
Next Article → Part 4: Migraine Aura—More Than Just Visual Disturbances
This article is part of the series Rethinking Migraine. Subscribe to the newsletter for updates on articles, courses, and live events.
If you are looking for continuing education credits on this topic, consider my Migraine Series: A Clinical Guide for Acupuncturists available through Net of Knowledge!
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