Symptoms: Chronic cough: Usually the first symptom. Initially the cough is intermittent, heavier in the morning, and later in the morning and evening or throughout the day, but the cough is not significant at night. In a few cases, the cough is not accompanied by sputum. In some cases, there is no cough despite significant airflow limitation. Coughing sputum: Coughing is usually followed by a small amount of mucus sputum, some patients have more sputum in the early morning; when combined with infection, the sputum volume increases, often with purulent sputum. Shortness of breath or dyspnea: It is the hallmark symptom of COPD and is the main cause of anxiety in patients. It appears only during exertion in the early stage, but gradually worsens to the point that shortness of breath is felt even during daily activities and even at rest. Wheezing and chest tightness: are not specific symptoms of COPD. Some patients, especially severe patients, have wheezing; tightness in the chest usually occurs after exertion and is associated with respiratory effort and isotonic contraction of intercostal muscles. Systemic symptoms: During the clinical course of the disease, especially in more severe patients, systemic symptoms such as weight loss, loss of appetite, peripheral muscle atrophy and dysfunction, mental depression and/or anxiety may occur. Hematochezia or hemoptysis may occur in the setting of co-infection. History characteristics: The disease process should have the following characteristics: 1, smoking history: most have a long history of heavy smoking. 2, occupational or environmental hazardous substances exposure history: such as longer-term dust, fumes, harmful particles or harmful gas exposure history. 3, family history: COPD has a tendency to gather in families. 4, age of onset and season of prevalence: most of the onset of the disease after middle age, symptoms tend to occur in the cold season of autumn and winter, often with repeated respiratory infections and a history of acute exacerbations. As the disease progresses, acute exacerbations become more and more frequent. 5. History of chronic pulmonary heart disease: Hypoxemia and (or) hypercapnia occur in the late stages of COPD, which can be complicated by chronic pulmonary heart disease and right heart failure. Signs Early signs may not be obvious. With the progression of the disease, the following signs are often present: 1. Visual and palpation: abnormal thoracic morphology, including hyperinflation of the chest, increased anterior and posterior diameters, widening of the inferior sternal angle (superior abdominal angle) under the glabella, and abdominal bulging; common shallow breathing, increased frequency, auxiliary respiratory muscles participate in respiratory movements, and in severe cases, contradictory thoracoabdominal movements are seen; when dyspnea worsens, the patient often adopts a forward sitting position; in hypoxemia, mucous membrane and skin cyanosis may appear. Lower limb edema and liver enlargement are seen in those with right heart failure. 2. Auscultation: Due to hyperinflation of the lungs, the cardiac and hepatic borders are narrowed and the pulmonary and hepatic borders are lowered, and the lungs may appear hyperclear on auscultation. 3. Auscultation: Breath sounds of both lungs may be reduced and the expiratory phase may be prolonged.