The most common factors for developing asthma are having a parent with asthma, having a severe respiratory infection as a child, having an allergic condition, or being exposed to certain chemical irritants or industrial dusts in the workplace.

Asthma is a chronic (long-term) condition that affects the airways in the lungs. The airways are tubes that carry air in and out of your lungs. If you have asthma, your airways can become inflamed and narrowed at times. This makes it harder for air to flow out of your airways when you breathe out.

Bronchial asthma is a chronic inflammatory disease of the airways characterized by bronchial hyperreactivity and a variable degree of airway obstruction.