Factors affecting respiratory function mainly include: 1, disease factors: pneumonia, tuberculosis, lung cancer and bronchial asthma and other diseases may cause ventilation and ventilation dysfunction, resulting in decreased respiratory function; 2, age factors: the older the patient’s ventilation function is lower; 3, physical and chemical factors: the inhalation of dust or smoke may lead to the patient’s airway edema, triggered by complications, which may lead to respiratory failure; 4, medications: analgesic drugs and antibiotics may lead to respiratory function of the patient is impaired; 5, the factor of obesity: the accumulation of fat may lead to decreased lung ventilation.