Acute exacerbation of chronic obstructive pulmonary disease (COPD) is characterized by worsening of respiratory symptoms, mostly cough, sputum, dyspnea, wheezing, chest tightness and other aggravating symptoms, as well as some non-specific changes such as loss of appetite. 1. Cough: patients with chronic obstructive pulmonary disease (COPD) often have chronic cough, which is more frequent and more severe in acute exacerbation; 2. sputum: patients with chronic obstructive pulmonary disease have white mucus sputum, occasionally with blood, and the amount of sputum increases in acute exacerbation, and there may be purulent sputum. 3. Shortness of breath or dyspnea: usually occurs during strenuous activities, and during acute exacerbation, shortness of breath and dyspnea may be felt during daily activities or even at rest. 4. Wheezing and chest tightness: patients may wheeze during acute exacerbation. 5. Others: Acute exacerbation can also appear non-specific manifestations such as decreased appetite and poor sleep. If patients with chronic obstructive pulmonary disease (COPD) experience acute exacerbation of the above symptoms, it is recommended that they go to the hospital in time and receive standardized treatment under the guidance of doctors.