The airflow limitation in bronchial asthma is completely reversible, which is related to the pathophysiological mechanisms involved in the occurrence of bronchial asthma. Bronchial asthma is a chronic airway inflammation involving multiple inflammatory cells. When this airway inflammation occurs, there can be edema of the airway mucosa as well as spasm and contraction of the smooth muscles outside the bronchi. However, this inflammation and smooth muscle spasm are reversible through medication or spontaneous improvement. Thus, many patients with mild asthma can achieve symptom relief without medication. In the case of some severe patients, even though the airflow is restricted, it can be reversed with the use of medications, and generally, the recovery is very quick.