Over thirty years ago clinical researchers first noticed a possible increase in the number of patients presenting to hospital with worsening asthma in the hours and days after a thunderstorm. Subsequently, this phenomenon has been noted, documented and researched in several countries of the world, especially in Australia, the UK and the United States of America. The problem seems to be worse when a thunderstorm occurs during a summer period after a period of relatively high pollen counts. During the windy conditions associated with thunderstorms large concentrations of pollen and spores circulate in the air where the moist condition breaks up the starch of the pollen into much smaller than usual granules which are then small enough to be breathed directly into the lungs where they produce an inflammatory reaction and worsening asthma.

I cannot stop thunderstorms so what can I do?
Those who usually have well controlled asthma are less at risk of worsening after a thunderstorm than those whose asthma is not well controlled. However, everyone with asthma is at some increased risk at the time of a thunderstorm and regular preventative therapy should be continued with extra doses of reliever medication as necessary. All with asthma should then consult their personal asthma action plan and follow the advice given there as to how increase their asthma medicines, when to start additional medicines, and when to seek urgent medical attention.