UK scientists say they have found a new cause behind much of the damage asthma causes.
Cells lining the airways are squeezed to destruction during an attack, their research shows.
And drugs to prevent this, rather than manage its aftermath, might break the cycle of harm, the Kings College London researchers told the Science journal.
The airways of people with asthma are sensitive to triggers such as pollen, pets and exercise.
They become inflamed or swollen, causing symptoms including coughing, wheezing and breathlessness.
