If you feel a queasy, uneasy sensation in your stomach during a migraine attack, it’s probably not from the late-night takeout you ate. According to a 2017 study in the Journal of Pain Research, nausea occurs in about 58% of people during a migraine episode—and that’s a conservative assessment.1 Data from an older, self-reported survey published in the journal Headache found most people experience vomiting and nausea during an episode, with estimates closer to 70 to 90%, respectively.2
For non-migraine folks, those numbers may seem surprising. After all, throbbing head pain and visual disturbances are typically viewed as the telltale signs that a migraine is on the horizon. So, how can symptoms that happen way down in the stomach have anything to do with the above-the-neck signs that most people associate with a migraine? For people living with migraine, nausea is just another piece of this complex puzzle.
Fortunately, we have some answers about why you feel nauseous with a migraine, and more importantly, tips on how you can stop the pain and discomfort before it goes too far.
What causes migraine with nausea and vomiting?
The who and why of migraine attacks are already a bit of a mystery, but symptoms can be Clue level head-scratchers. Even though nausea tops the list of migraine symptoms for many people, why this happens is not clear-cut. The good news is experts have a few theories that shed light on the link between migraine and nausea.
Migraine involves certain areas of the brainstem.
A migraine commonly includes things like nausea, but sometimes vomiting and diarrhea too. Jack Schim, M.D., F.A.H.S., F.A.A.N., co-director of the Neurology Center of Southern California, tells SELF that experts think at least part of this is due to migraine affecting different brainstem areas involved in autonomic functions—the things your body just does automatically—such as digestion. The idea is that migraine attacks irritate the nerves that activate this system, triggering those not-so-fun symptoms.
Migraine decreases serotonin levels.
Another theory according to Medhat Mikhael, M.D., pain management specialist and medical director of the non-operative program at the Orange Coast Medical Center’s Spine Health Center, is that migraine decreases serotonin levels in the brain, which is believed to contribute to nausea. Serotonin is generally known as the happy chemical keeping our mood on an even keel (among many other important functions in the body). So, it’s no surprise that a decrease in our feel-good chemicals could have noticeable side effects. Dr. Mikhael also says that a decrease in serotonin can trigger motion sickness, another uneasy feeling.
Migraine triggers changes in blood vessels in the brain.
It’s thought that migraine attacks change blood vessel diameter in the brain. Typically, the diameter increases in size and tugs on the meninges (shock absorber between your skull and brain), which causes throbbing or pulsating pains. “When these changes affect parts of the brain that regulate nausea and vomiting, you may experience stomach problems,” Clifford Segil, D.O., a neurologist at Providence Saint John’s Health Center in Santa Monica, California tells SELF.
He says one area of the brain, in particular, is on the shortlist of suspects that may trigger nausea and vomiting in people with migraine. That area is called the rostral dorsal medulla and essentially relays sensory information from the spinal cord to the brain. According to a 2014 study published in the Journal of Headache and Pain, nausea in the prodrome phase of a migraine—basically the opening act—is linked to activity in this part of the brain.3
Migraine causes a certain neurotransmitter to be released.
Migraine pain is linked to the release of a neurotransmitter—one of your body’s messengers—called calcitonin gene-related peptide (CGRP).4 In fact, certain migraine medications act on this very thing to try to stop a migraine attack from occurring in the first place. Dr. Schim says this neurotransmitter is also prevalent in the gut, which could have something to do with that I’m-going-to-hurl feeling when you have a migraine.
Types of migraine and headaches that can cause nausea
By now you’ve probably figured out that migraine attacks are complicated—we don’t yet know exactly what triggers all the symptoms. What we do know is that certain types of migraine are more likely to cause nausea and vomiting. Oh, and to make matters even more confusing, some headaches—that are not migraines—may also make you toss your cookies.