By Gary Fitzgerald
Asthma was once considered a single, though complex, disease. Now it’s recognized as a spectrum of diseases, with genetic and environmental factors playing a role in airway inflammation and hyperreactivity that causes coughing, wheezing and shortness of breath.
Severe asthma is one form of the disease. It’s estimated that 5-10 percent of people with asthma have severe asthma – which is diagnosed when symptoms are not well controlled by high-dose inhaled controller medications or when two or more asthma flares in a 12-month span require oral corticosteroids.