Compensatory emphysema is a normal physiological process, because the total area of the lung decreases after partial lung resection, and in order to ensure the body’s oxygen needs, the other side of the lung becomes compensated for the expansion, thus forming compensatory emphysema. Generally, compensated emphysema is asymptomatic. However, if the lung loses this function, it is non-compensated emphysema. What are the examination methods for emphysema? 1.X-ray examination The thorax is dilated, the rib space is widened, the ribs are parallel, the diaphragm is lowered and flattened, and the translucency of the two lung fields is increased. x-ray is mainly used to detect skeletal lesions, but it is also useful for detecting soft tissue lesions. Common examples are chest X-rays, which are used to diagnose lung diseases such as pneumonia, lung cancer or emphysema, and abdominal X-rays, which are used to detect intestinal obstruction, free gas and free fluid. 2.Electrocardiogram is usually abnormal and sometimes may show low voltage. The heart is excited by the pacing point, atrium and ventricle successively in each cardiac cycle, accompanied by bioelectric changes, and the graph of various forms of potential changes elicited from the body surface through the electrocardiographic tracer is called electrocardiogram (ECG for short). 3.Respiratory function test It is important to diagnose obstructive emphysema with a residual air volume/total lung volume ratio >40%. Pulmonary function test is one of the necessary tests for respiratory diseases. Pulmonary function test includes ventilation function, air exchange function, respiratory regulation function and pulmonary circulation function, etc. It is important for early detection of lung and airway lesions, assessment of disease severity and prognosis, evaluation of the efficacy of drugs or other treatments, identification of the causes of dyspnea, diagnosis of lesion sites, assessment of lung function on the tolerance of surgery or labor intensity tolerance and monitoring of critically ill patients. 4.Blood gas analysis If there is obvious hypoxic carbon dioxide retention, the partial pressure of arterial blood oxygen (PaO2) decreases and the partial pressure of carbon dioxide (PaCO2) increases, and there may be loss of compensatory respiratory acidosis with a lower pH. 5.Blood and sputum examination Generally there is no abnormality. Blood test is the most general and basic blood test. It is a test to determine anemia, cholesterol, diabetes, various infections, kidney function, calcium, liver function, blood disorders and physical abnormalities in human body through blood analysis. It is one of the most common laboratory tests performed in hospitals. Blood tests should be assigned by medical order, and physicians use the results to clarify or support the diagnosis, to monitor or decide on treatment, and to make screenings for undetermined conditions. Sputum immunology test is one of the sputum tests to determine immunoglobulins in sputum.