Asthma is not chronic obstructive pulmonary disease. Asthma has an early onset, usually in childhood, while patients with chronic obstructive pulmonary disease generally have an older onset, in middle and old age. Asthma is mainly characterized by wheezing, and the daily symptoms change very quickly, and the symptoms are more obvious at night and early in the morning; while for patients with chronic obstructive pulmonary disease, they usually have long-term chronic cough and sputum symptoms, and gradually develop dyspnea after activity, and the symptoms are slow and progressive. At the same time, asthma is generally associated with allergies, and allergen detection is generally positive, while allergens are generally negative in patients with chronic obstructive pulmonary disease. When pulmonary function tests are done, chronic obstructive pulmonary disease shows persistent airflow limitation, while when pulmonary function tests are done for asthma, the bronchodilator test shows very good improvement in pulmonary function. Asthma generally has a history of allergies, rhinitis, eczema, and a family history of asthma. In GOLD or GINA in 2015, which is the global initiative for slow-onset lung, the overlapping syndrome of asthma and slow-onset lung is proposed. In this disease process, patients with persistent airflow limitation on pulmonary function tests, with several asthma and COPD are the corresponding features of slow-onset lung, which is called slow-onset lung asthma overlap syndrome.