What is a major risk factor for bronchial asthma?

Narrowing of airways is a significant risk factor for bronchial asthma because this condition involves the inflammation and constriction of the bronchial tubes, which directly leads to restricted airflow. When the airways narrow, it becomes difficult for air to pass through, resulting in the characteristic symptoms of asthma, such as wheezing, coughing, and shortness of breath.

This airway narrowing can be triggered by various factors, including allergens, irritants, respiratory infections, and exercise, all of which can exacerbate asthma symptoms. Over time, repeated narrowing can lead to more permanent changes in the airway structure, underscoring its critical role in asthma pathology.

While aging, shortness of breath, and obesity may have associations with asthma, they do not directly represent the physiological changes that characterize the condition as narrowing of the airways does.