You're Not Just Stressed. Your Migraine Is Written in Your Genes.

Your MTHFR gene encodes methylenetetrahydrofolate reductase, an enzyme that sits at the center of your methylation cycle. This cycle is responsible for building neurotransmitters, regulating gene expression, and controlling the amino acid homocysteine. When methylation is working properly, homocysteine gets converted to methionine, and your brain has the substrates it needs to produce serotonin and regulate blood vessel tone.

The MTHFR C677T variant, present in roughly 40% of people with European ancestry, reduces the enzyme’s activity by 40-70%. This means your cells struggle to complete the methylation cycle. When methylation is impaired, homocysteine accumulates, and your brain’s ability to regulate serotonin and cerebrovascular tone deteriorates. Elevated homocysteine is one of the strongest independent risk factors for migraine with aura. It’s also strongly associated with more frequent migraines and worse outcomes.

When your MTHFR variant is active, a normal trigger,say, a 6 AM wake-up time or a cup of coffee,can tip your brain from stable to migraine-vulnerable. Your blood vessels become hyperresponsive. Your serotonin buffer shrinks. Your migraine threshold drops. The genetic variant doesn’t cause the migraine by itself, but it loads the gun, and then any trigger can fire it.

Your CACNA1A gene encodes a voltage-gated calcium channel expressed on neurons throughout your brain, especially in the cortex and trigeminal system. Calcium channels control how neurons fire. They regulate the electrical excitability of your brain. When calcium channels work normally, your neurons have a stable firing threshold, and migraine-triggering waves of activity (called cortical spreading depression) don’t initiate easily.

Mutations in CACNA1A, present in roughly 1-5% of people with familial migraine (migraines that run in families), create calcium channels that fire more easily or stay open longer than they should. This lowers the threshold for cortical spreading depression, the neurological wave that is thought to initiate a migraine attack. If you carry a CACNA1A variant, your brain’s electrical stability is compromised. Smaller stimuli can trigger the cascade that leads to migraine. This is why people with CACNA1A variants often have migraines triggered by things that seem trivial to others: a light change, a slight stress, a slight altitude change.

For you, migraines may feel like they come from nowhere because they do. Your brain is so electrically sensitive that the migraine threshold is chronically low. What others view as routine daily challenges feel, to your brain, like a massive electrical perturbation.

Your NOS3 gene encodes endothelial nitric oxide synthase, an enzyme that produces nitric oxide in the lining of your blood vessels. Nitric oxide is a signaling molecule that tells blood vessels to relax and dilate. It controls blood pressure, blood flow distribution, and the tone of cerebral blood vessels. When nitric oxide production is normal, your blood vessels respond flexibly to changes in demand and stress.

The Glu298Asp variant in NOS3, carried by roughly 30-40% of the population, reduces the amount of nitric oxide your endothelial cells produce. Lower nitric oxide means your cerebral blood vessels have reduced flexibility and are more prone to the constriction-dilation cycles characteristic of migraine. You might experience this as a migraine that begins with a tight, constrictive feeling in the head, followed by throbbing and pain as vessels dilate. The vascular dysregulation is baked into your endothelial cells.

With a NOS3 variant, your blood vessels are less responsive to your body’s own vasodilatory signals. They’re stiffer, less flexible, and more reactive to stress, heat, and hormonal changes. This is why migraine triggers often feel vascular to you: certain foods make the headache worse, heat makes it worse, or hormonal shifts (like the estrogen drop before menstruation) reliably trigger attacks.

Your COMT gene encodes catechol-O-methyltransferase, an enzyme that breaks down dopamine, norepinephrine, and epinephrine. These neurotransmitters are critical for pain modulation. Dopamine and norepinephrine activate pain-suppressing pathways in your brain and spinal cord. When COMT is working normally, these pain-suppressing neurotransmitters are available in the right amounts to dampen pain signaling from the trigeminal nerve (the nerve central to migraine pathophysiology).

The COMT Val158Met variant, present in roughly 25% of people with European ancestry as a homozygous slow variant, slows the breakdown of dopamine and norepinephrine. This sounds beneficial, but it’s not. Slow COMT variants result in excessive dopamine accumulation in certain brain regions, which paradoxically amplifies pain signaling in the trigeminal system and worsens migraine severity and frequency. People with slow COMT variants have lower pain thresholds and higher migraine frequency. They’re also more sensitive to stimulants like caffeine, which further raises dopamine levels.

If you have a slow COMT variant, your pain-suppressing neurotransmitter system is out of balance. You don’t clear dopamine and norepinephrine quickly enough, which messes with your pain modulation. Coffee makes it worse. Stress makes it worse (stress raises epinephrine, which COMT can’t clear quickly). You might describe your migraines as more frequent or more severe than people around you, even when exposed to the same triggers.

Your SLC6A4 gene encodes the serotonin transporter, the protein that removes serotonin from the synaptic space after it’s been released by neurons. Serotonin is central to migraine pathophysiology. Low serotonin availability is associated with migraine, and triptans (the first-line acute migraine treatment) work partly by boosting serotonin signaling. When serotonin transporter activity is normal, serotonin is recycled efficiently, and your brain maintains stable serotonin signaling across networks involved in pain, mood, and vascular tone.

The 5-HTTLPR short allele in SLC6A4, carried by roughly 40% of the population, results in lower serotonin transporter expression. This means less serotonin is cleared from synapses, which sounds good but creates the opposite problem: lower overall serotonin availability, because the transporter also regulates serotonin synthesis. With a short allele variant, your brain struggles to maintain stable serotonin levels, and this instability is central to migraine initiation and the vasoconstriction-dilation cycles that characterize migraine attacks. Additionally, the serotonin instability makes you more vulnerable to mood changes, stress sensitivity, and hormonal triggers.

If you carry the SLC6A4 short allele, serotonin triggers matter to you. Certain foods (like aged cheese with tyramine) can destabilize serotonin and trigger migraines. Hormonal fluctuations impact your serotonin tone, which is why many people with this variant experience menstrual migraines. Stress and sleep deprivation deplete serotonin further. You might feel that your mood and migraines are deeply linked: when you’re anxious or depressed, migraines are more frequent.

Your TRPM8 gene encodes a ion channel on sensory neurons that detects cold and menthol. This channel is expressed extensively in the trigeminal nerve, the nerve that is central to migraine pathophysiology. TRPM8 activation signals “cold” to the brain, but it also modulates pain and temperature sensation more broadly. When TRPM8 function is normal, your sensory neurons have a stable activation threshold, and random temperature changes or sensory stimuli don’t trigger pain.

Variants in TRPM8, identified in GWAS studies and present in roughly 15-20% of the population, alter the activation threshold of this cold-sensing channel. Variants associated with migraine risk lower the threshold for trigeminal neuron activation, making your sensory neurons hyperresponsive to temperature changes and other sensory inputs. This means your trigeminal nerve, already involved in migraine, is even more easily triggered by cold exposure, temperature shifts, or certain tactile sensations. Cold foods, cold air, or exposure to air conditioning can initiate or worsen migraines.

If you have a TRPM8 variant, you probably notice that cold is a reliable migraine trigger. Jumping into a cold pool, eating ice cream, or being in an over-air-conditioned room can start a migraine. Your sensory system is tuned to be exquisitely sensitive to temperature change. This is a feature of your neurobiology, not a character flaw or a sign you’re not tough enough.