Chronic obstructive pulmonary disease (COPD) is a preventable and treatable common disease characterized by persistent airflow limitation. Airflow limitation progresses with an increased chronic inflammatory response of the airways and lungs to harmful particles or gases. Acute exacerbations and comorbidities affect the overall severity of the disease in patients. The disease has become an important public health problem affecting human health because of its high prevalence, high mortality rate, and socioeconomic burden. COPD currently ranks as the 4th leading cause of death worldwide. Epidemiological surveys in China show that the prevalence of COPD in people over 40 years of age is 8.2%, which is an alarmingly high prevalence.