The warning is in place across a large part of England and Wales from 9am this morning until 7pm tonight.
Worryingly, this gloomy weather could put one in 12 Britons with asthma at a risk of 'thunderstorm asthma'.
The common lung condition that causes occasional breathing difficulties affects around 5.4 million people in the UK.
Now, GP at LloydsPharmacy Online Doctor, Dr Neel Patel, has explained how stormy weather could fuel an attack.
Dr Patel said: “Thunderstorm asthma is the name given to a phenomenon that links asthma attacks and stormy weather.
“Essentially, stormy weather can increase instances of asthma attacks.
“Thunderstorm asthma can occur in anybody with asthma, however, it’s most common in people who also experience hay fever.”
There are two reasons why this type of weather can trigger more asthma attacks.
The doctor explained the first one comes down to wind drawing more pollen into the already moist air which can break these pollen granules into smaller particles and they can get deeper into your lungs - a recipe for asthma symptoms.
“Added to this, the air can feel very close and humid before a storm,” the doctor said.
“For people with asthma, this can trigger a tight chest, cough and difficulty breathing.”
The symptoms of thunderstorm asthma are the same as those of asthma, so you can expect wheezing, breathlessness, tight chest and coughing.
The doctor recommended to monitor the weather forecast and follow this asthma advice if you are at risk of thunderstorm asthma:
- Keep your inhaler handy - while it’s always a good idea to have your reliever nearby, it’s even more important during thunderstorms
- Have an asthma action plan - this plan details which medicines you can take to prevent attacks, what to do if your symptoms are getting worse and the emergency action to take in the event of an asthma attack
- Stay indoors - because the pollen concentration will be greatest outside, you should stay indoors with the windows closed as much as possible before, during and after the storm.
- Wear a mask outside - although not much research has been done into the effectiveness of wearing a mask, it’s thought this can help filter out some of the pollen particles from the air you inhale
- Avoid other triggers - before, during and after a storm, you should avoid anything that can worsen your symptoms
- Take your usual medicine - continue taking your usual medication, even if you don’t yet feel symptoms worsening.