Severe asthma refers to uncontrolled asthma with frequent exacerbations despite higher levels of treatments. It accounts for 5% to 10% of all asthma patients.

Patients with severe asthma have a poor quality of life due to frequent exacerbations and low lung function. These patients also have a much higher health and socioeconomic burden.

The number of patients with severe asthma continues to increase due to population aging, climate change, and environmental pollution.

High disease burden of asthma (by a single disease)