Bronchial asthma is a common and frequent disease of the respiratory system. In recent years, the understanding of airway inflammation in the pathogenesis has led to significant advances in treatment. However, the advances in treatment do not parallel the current status of bronchial asthma control. A survey of the current status of asthma control in the Asia-Pacific region found that half of the respondents had asthma symptoms and 43% of the patients had been hospitalized or sought emergency care for asthma in the past year, and the disease load remained quite severe (Lai CKW 2003). In addition, the mortality rate of patients with bronchial asthma has been on the rise for nearly 30 years (Lange P 1996, McFadden ER Jr 1997) and has become a serious global public health problem. Foreign studies have found that about half of asthma patients do not accurately perceive the severity of airway narrowing (Barnes PJ 1992, Teeter JG 1998, Put C 1999). 26-34% of asthma patients do not perceive symptoms in the presence of a marked decrease in FEV1 (Magadle R 2002, Lai CKW 2003). these so-called symptom-impaired patients are prone to These so-called symptom-naïve patients are prone to structural airway remodeling and irreversible airway obstruction due to underestimation of the severity of the airway obstruction and long-term failure to treat it. In addition, in acute exacerbation or worsening of the disease, patients underestimate the severity of the condition and fail to seek medical attention in a timely manner, which delays treatment and leads to serious consequences such as fatal exacerbations (Magadle R 2002). Therefore, the mortality rate of patients with retarded symptom perception is significantly higher than that of patients with normal symptom perception (Kikuchi Y 1994). Another 27-31% of patients with asthma have many symptoms with minimal impairment of pulmonary function or normal pulmonary function tests. These patients are over-medicated and over-medicated with medications due to overestimation of the disease, resulting in waste of medical resources and unnecessary medication side effects (Nguyen BP 1996, Teeter JG 1998). It is obvious that the deviation of symptom perception in bronchial asthma patients is one of the important factors affecting the overall control of asthma, and it is important to identify these asthma patients with deviations in symptom perception and provide targeted treatment.