With climate change intensifying how often we deal with heat waves and pollution, it’s important to consider these risk factors when it comes to migraine, the researchers wrote.
Why do these factors raise the risk of migraine?
It’s important to note that the study didn’t prove that air pollution, heat, and lower humidity levels cause migraines—it just found a link between them. But doctors say there’s likely something here.
Air pollution can spark neuroinflammation (the immune system’s inflammatory response in the brain and spinal cord), which is a risk factor for migraine, Sana Ghafoor, MD, neurologist at Tufts Medical Center, tells SELF. This may cause a release of pain chemicals like calcitonin gene-related peptide (CGRP) and substance P that can lead to a migraine, Dr. Ghafoor says.
Air pollution may be particularly problematic for people with allergies who also struggle with migraines, Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, California, tells SELF. The body may see air pollution as an allergen and mount an immune response, which can spark a migraine in people who are sensitive to this trigger, he explains.
Then, there’s the fact that heat can impact blood vessels and nerves. “When people heat up, nerves and blood vessels in tight locations can become irritated, as the diameter of a blood vessel or nerves increases with heat,” Dr. Segil says. That, too, can trigger a migraine. You’re also more susceptible to getting dehydrated when it’s hot out, Dr. Ghafoor says: “If you’re overheated and dehydrated, those can also trigger migraines.”
Dr. Segil points out that high humidity common in the spring and summer (and not just that related to air pollution) can trigger migraines too. High humidity causes you to sweat and lose water, which can decrease the amount of blood in your blood vessels (if you don’t replace it), Dr. Segil says. “This decreases the diameter of blood vessels and can cause headaches, just like an increased blood vessel diameter,” he says.
