Every three seconds somebody in the UK has an asthma attack, new figures suggest.
Data from the charity Asthma UK shows that those with asthma are having more attacks every year than previously thought.
It surveyed more than 10,000 people with asthma, who reported having an attack on average twice a year.
With 5.4 million people in the UK currently having treatment for asthma, experts calculated that this averaged one attack every three seconds.
Previous studies have suggested that the average was more like one every 10 seconds.
Asthma attacks can be life-threatening, with three people on average dying every day from an attack.
The condition affects the airways, narrowing them and making it harder to breathe.
Triggers can include cold air, coughs and colds, and grass pollen.
Dr Andy Whittamore, clinical lead at Asthma UK, said: “It is shocking to think that every three seconds in the UK someone could be having an asthma attack, a terrifying experience than can cause distress and in some cases prove fatal.
“Asthma attacks do not come out of the blue and if people recognise the tell-tale signs that an attack is about to strike, they can get the help that could save their life.”
The charity warns that if people need to use their reliever inhaler (usually a blue colour) three or more times a week, or are are waking up at night because of their asthma, they should contact their GP.
They should also seek help if their symptoms, such as wheezing or a cough, are getting worse or are interfering with their usual activities.
Those with a preventer inhaler (usually coloured brown) should take it daily to help build up protection against asthma attacks.
Kelly May, 31, a hairdresser from London, has had hundreds of asthma attacks since she was a year old.
She said: “Having an asthma attack can feel like being a fish out of water and it’s terrifying.
“No matter what I do, I can’t catch my breath. I try not to panic but in the back of my mind I know I need to get to A&E or it could be fatal.
“People think that asthma isn’t serious, but I’ve had asthma attacks at work and it’s terrifying for those around me.
“The aftermath of an asthma attack can also be exhausting and horrible – it can take me weeks until I feel normal again.
“In winter, I must be especially careful as the slightest cold can land me in hospital fighting for my life.”
NHS data shows there were more than 77,000 hospital admissions for the condition last year.