• Posted November 7, 2025

Thunderstorm Is Approaching, Brace For An Asthma Attack

The flash of lightning and roar of thunder can be quickly followed by the wheezing gasp of an asthma attack, a new study says.

Thunderstorms appear to trigger sharp increases in asthma-related ER visits, researchers are scheduled to report Saturday at the American College of Allergy, Asthma & Immunology’s annual meeting in Orlando, Florida.

“These results confirm that thunderstorms can pose a serious health risk for people with asthma, even in the United States,” said lead researcher Dr. Diala Merheb, an internal medicine resident at the University of Kansas Medical Center.

“Because storms are unpredictable, patients and health care providers should include storm-specific precautions in asthma action plans,” she said in a news release.

“Thunderstorm asthma” is a well-documented phenomenon that’s been acknowledged by the World Allergy Organization, researchers said in background notes.

However, studies have been limited in pollen-heavy parts of the U.S., so the threat to Americans is not well-understood, researchers said.

For the study, researchers analyzed nearly 4,500 asthma-related ER cases across three Wichita, Kansas, hospitals between 2020 and 2024.

About 14% of all cases occurred on just 38 days with thunderstorms, an amount of time representing only 2% of the calendar days in the study period, results show.

Patients made an average of nearly 18 asthma-related ER visits per day during thunderstorms, compared to just three during calmer weather.

Harvard Medical School says thunderstorms can make asthma attacks more likely due to the way the weather events unfold:

• Cold downdrafts concentrate pollen and mold, and these allergens are then swept up into humidity-thick clouds.

• During a thunderstorm, wind, humidity and lightning break the particles down to a size that can easily be inhaled deep into the lungs.

• Wind gusts during a storm concentrate the small particles, making it likely large amounts will be inhaled.

“If you or your child has asthma, it’s smart to think about thunderstorms the same way you prepare for high-pollen days or cold weather,” researcher Dr. Selina Gierer, an allergist with the University of Kansas Health System, said in a news release. “Understanding triggers and having a clear plan can help avoid emergency room visits.”

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

More information

Harvard Medical School has more on thunderstorm asthma.

SOURCE: American College of Allergy, Asthma & Immunology, news release, Nov. 6, 2025