Across the world, severe asthma epidemics have been triggered by the fierce winds and torrential downpours of thunderstorms. Since the 1980s, there have been several outbreaks reported in the United Kingdom, Canada, Italy, Australia and the United States.
Thunderstorm asthma can even be deadly in some cases.
In November 2016, hundreds of people were hospitalized and at least four died as a thunderstorm triggered an asthma epidemic across portions of southeastern Australia, according to the Washington Post.
Thunderstorm asthma occurs during seasons when there are high concentrations of pollen in the air, the study reported.
During thunderstorm activity, pollen allergens and mold spores can trigger asthma symptoms, sometimes for people who may not have suffered from them before.
According to the study, the largest thunderstorm asthma outbreak ever recorded occurred in London in June 1994. Out of 640 patients who reported symptoms, 283 were not known to have been asthmatic.
Since thunderstorms occur swiftly and do not allow much data for scientists to study in their wake, there is still much to be learned about the exact mechanisms behind these outbreak events.
Thunderstorm winds may pull in full pollen grains, which get broken down into fragments within the storm, according to a 2006 study published in the European Journal of Allergy and Clinical Immunology. The smaller fragments may then be dragged to the surface by storm winds.
In addition, it is thought that a higher concentration of pollen grains combined with the storm's heavy rainfall causes the grains to swell and eventually rupture into tiny fragments that are then dispersed into the air. When inhaled, these smaller particles are more detrimental than whole pollen grains because of their size.
"These allergens can likely penetrate deeper into the lung, provoking more severe symptoms," the study reported. The study also found evidence of increased mold spore counts have been found during thunderstorms.
Fungal spores can react to changes in humidity and temperature as well and afflict people who have other respiratory problems, not only those who suffer from seasonal allergies.
"Not everyone who gets thunderstorm asthma has had it before. They have normally had severe pollen allergic rhinitis and most have been found to be allergic to ryegrass. Presumably the massive load of small allergenic particles being inhaled straight into the lung trigger these attacks," according to Australian Society of Clinical Immunology and Allergy.
In addition to thunderstorms, temperature and humidity changes can worsen symptoms in patients suffering from asthma, according to Asthma UK.
Cold and damp air can impact the sensitive airways of people suffering from asthma and can trigger "coughing, wheezing, shortness of breath and tightness in the chest," the organization reports.
Staying indoors during thunderstorms, managing symptoms, using the proper medication and consulting with a medical professional can help those suffering from allergies and asthma reduce the effects weather has, according to the organization.
In addition, carrying a rescue, or reliever inhaler at all times can help sufferers take immediate action during a thunderstorm asthma attack, according to the Washington Post.