Why Do Migraines Make You Nauseous
“The first thing you think about when someone mentions migraines is “”Oh no, I have one coming on.”” The next thing you might think is “”I hope it doesn’t last long,”” but then your head hurts so much you can barely breathe through your nose or open your mouth. So what causes this severe pain? And why do these headaches happen at all?
Migraine pain is due to an imbalance between two chemicals in the human body — nitric oxide (NO) and vasoactive intestinal peptide (VIP). When NO levels are high, as they usually are during a headache-free period, VIP, a chemical produced by the hypothalamus, tells nerve cells throughout the nervous system to release their contents, including pain-producing neuropeptides such as substance P. But when VIP levels drop low, as they do during a migraine episode, those same nerves become confused, releasing both substances simultaneously, causing them to fire off neurotransmitters even faster than usual. This results in increased blood flow and inflammation in the brain’s blood vessels, increasing pressure inside the skull, and sending excruciating pain signals from the head to the brain.
While scientists are still studying how exactly this process works, we know that serotonin plays a role in the brain during a migraine attack, and there are a lot of serotonin receptors in the gut, notes Dr. Joshua A. Bonaparte, associate professor of neurology and director of clinical research at Brigham and Women’s Hospital in Boston. Serotonin is released into the bloodstream when food reaches the small intestine, where it binds with specific receptors in the gut wall that send messages to stimulate peristalsis, or muscle contractions. The idea that gastric stasis, which is when the stomach empties more slowly than normal, is the underlying cause of nausea in migraine has been disproven.
“”It’s not because the stomach is full that people feel nauseated,”” says Bonaparte. “”People who are vomiting don’t experience nausea.”” In fact, he adds, some patients may vomit after eating during an aura phase before a migraine occurs, while others may eat only soft foods to avoid discomfort.
So what does cause nausea? One culprit could be a medication called dihydroergotamine mesylate, which is used to treat cluster headaches and prevent migraines caused by vascular spasms of the arteries leading to the brain. Dihydroergotamine mesylate constricts the smooth muscles in the walls of veins surrounding the brain and spinal cord, preventing blood from flowing out of the veins and creating pooling that leads to swelling. Patients taking this drug will often experience lightheadedness, dizziness and nausea, according to information provided by its manufacturer. Another possible culprit is sumatriptan, a treatment for migraine sufferers that stimulates serotonin receptors in the brain and neck area to relieve pain and nausea symptoms. If you’re also experiencing nausea while using this drug, lowering the dose or changing brands might help.
Other conditions associated with nausea include depression, anxiety disorders, panic attacks, schizophrenia and bipolar disorder. Eating too little or having a poor diet can make nausea worse, but if you’ve ruled out other possibilities, Bonaparte recommends talking to your doctor about trying antiemetics, drugs designed specifically to reduce nausea. He suggests starting out with dimenhydrinate (Dramamine), metoclopramide (Reglan) or chlorpromazine (Thorazine), depending on your particular situation.
Most experts agree that the best way to manage nausea is simply to wait it out — unless the condition becomes dangerous, in which case medical intervention is required. There are several ways doctors can use medications to combat nausea without resorting to surgery or radiation therapy. For example, Bonaparte uses prochlorperazine (Compazine) intravenously to control nausea during chemotherapy regimens, particularly in children.
But perhaps the most important way to deal with nausea is to keep hydrated. Drink plenty of fluids like water, tea, juice and sports drinks, especially noncaffeinated ones, and eat salty snacks like pretzels, crackers and cheese sticks to stay well-nourished. Avoid greasy or spicy foods, which can worsen nausea. If none of these tricks work, try ginger ale mixed with saltines, or take acetaminophen (Tylenol) to ease nausea and fever. Antiemetic drugs should never be taken orally, since the patient won’t absorb any of the medicine, and nausea pills shouldn’t be combined with alcohol or any prescription or over-the-counter medicines, as doing so can affect the effectiveness.
If you suffer from migraines, it’s likely that you’ll be prescribed a variety of treatments over time, and it’s important to remember that the goal isn’t necessarily to get rid of the headache completely, but rather to minimize the duration and severity of each individual attack.”