Two specific weather patterns may be responsible for triggering debilitating migraines in millions of Americans, according to a new study. Migraines, which affect 12 to 15 percent of the U.S. population—roughly 40 million people—are severe, recurring headaches often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. While there are dozens of known triggers, ranging from poor posture to intense odors or dietary indulgences like red wine and chocolate, pinpointing individual triggers can be a lengthy trial-and-error process.
Weather as a Migraine Trigger
Doctors and meteorologists have now focused on weather as a little-understood cause of migraines. In a study set to be presented this week, researchers analyzed weather patterns in the northeastern United States alongside headache diaries of patients with episodic migraines (15 or fewer per month). They identified two weather patterns associated with the highest risk of new-onset headaches.
The first pattern is an approaching cold front, or low-pressure system, accompanied by rain or snow. The second, known as the Bermuda High, involves increased air pressure, bringing sweltering heat, high humidity, and rain or storms. Experts believe that changes in air pressure and precipitation may irritate blood vessels and sensitive nerves in the brain, triggering migraines.
How Weather Triggers Migraines
When storms or fronts move in, barometric pressure drops, causing blood vessels in the brain to expand. This stretching of pain-sensitive nerves can trigger inflammation and a migraine. Environmental shifts have also been shown to affect levels of the neurotransmitter serotonin, which can further increase inflammation.
"Weather is one of the most common triggers for attacks of migraine headache," said Dr. Vincent Martin, study author and director of the Headache and Facial Pain Center at the University of Cincinnati's Gardner Neuroscience Institute. "Our investigation suggests that specific storm patterns may help explain why weather-related headaches and migraines are so frequent in Cincinnati and the Midwest region."
Study Details and Findings
The findings are being presented at the American Headache Society Annual Scientific Meeting in Orlando from June 4 to June 7. Researchers compared thousands of headache diary entries from migraine patients in the northeastern U.S. participating in the HALO-EM and HALO-LTS studies, which were clinical trials for fremanezumab (brand name Ajovy). They linked headache data to daily weather records from the National Climatic Data Center, tracking four years of weather patterns in three-day windows.
"What is significant about this headache research is that we are one of the first to look at weather patterns with a combination of variables, instead of a single weather variable," Martin said. "We further examined those weather patterns by region and season."
Role of Preventive Medication
The study also found that at least six months of treatment with Ajovy significantly reduced the rate of migraines across all weather patterns, including those identified as strong triggers. Ajovy is a once-monthly or once-every-three-months injection that targets calcitonin gene-related peptide (CGRP), a protein that transmits pain signals and induces inflammation in migraine patients. It is FDA-approved for adults and children aged six to 17.
"We saw the weather and headache relationship wiped out with the use of this medication," said Dr. Fred Cohen, co-investigator and faculty member at the Icahn School of Medicine at Mount Sinai. "We started to notice its effectiveness as early as one month after the start of the medication."
Implications and Recommendations
The researchers noted that while more studies are needed, the findings may offer clues for millions with migraines. "This is one of the first studies to suggest that a preventive medication might reduce the likelihood of a weather-associated headache," said Dr. Brinder Vij, lead study author and director of the Division of Headache Medicine at the University of Cincinnati Health.
For non-medical interventions, experts and patients recommend hydrating, drinking caffeine, applying a cold compress or ice pack to the head, gentle massage to the temples and shoulders, and resting in a dark, quiet room.
