With thunderstorms predicted in many parts of the country this week, Asthma UK is offering important advice to the 5.2 million people in the UK with asthma.
An American study, published in the journal Thorax, found that asthma-related hospital visits were 3% higher on days that followed thunderstorms than on days that did not.
During thunderstorms, large quantities of pollen can be released into the air, which can trigger asthma symptoms and raise the risk of an emergency admission six-fold.
On an average day, more than 200 people will be admitted to hospital with potentially life-threatening asthma attacks, so the increased risk during volatile weather means it is even more important for people with asthma to keep their asthma medicines with them.
It is believed that during thunderstorms, downdraughts of cold air sweep up high concentrations of pollen and spores. These allergenic particles are then thrust into the air, where the moisture breaks them up into pieces that can penetrate deep into the lungs.
This can induce attacks even in those who have previously only had mild asthma. During thunderstorms, it is therefore best to stay inside and close windows to keep allergens out.
Vikki Knowles, Clinical Lead at Asthma UK adds: "Unfortunately we can't control the weather but by taking the right steps early enough we can certainly help to control asthma symptoms. Having a personal asthma action plan can really help, showing you how to increase your asthma medicines safely if you notice your symptoms getting worse."