Asthma Chronic Obstructive Pulmonary Disease Overlap Syndrome (ACOS) is a syndrome of persistent airflow limitation with asthma and chronic obstructive pulmonary disease (COPD). Clinical authorities have proposed the concept of Asthma Chronic Obstructive Pulmonary Disease Overlap Syndrome (ACOS), which clearly indicates that ACOS is a persistent airflow limitation accompanied by asthma and chronic obstructive pulmonary disease (COPD) characteristics. The diagnostic criteria for COPD are exertional dyspnea, recurrent cough and sputum, persistent airflow limitation, and pulmonary function tests of first-second forced expiratory volume (FEV1)/first-exertion spirometry (FVC) <0.7 after the use of bronchodilators. After meeting the diagnostic criteria for COPD, the 2014 Spanish guideline criteria were used: meeting two main criteria or one main criterion plus two secondary criteria. 1. Three major criteria (1) Significant positive bronchodilator response (>15% increase in FEV1 after inhalation of bronchodilators and exceeding baseline values by more than 400mL). (2) Increased sputum eosinophils (>2.5%). (3) History of asthma before 40 years of age. 2. Three secondary criteria (1) Elevated total IgE level (>150ug/L). (2) Personal history of allergy. (3) 2 or more positive bronchodilator responses (>12% increase in FEV1 after inhalation of bronchodilators and exceeding baseline values by 200 ml. Prompt medical attention is recommended for patients considered to have asthma-dyslipidemia overlap syndrome.