Pulmonary function measurements are judged according to the patient’s own basic clinical signs and symptoms, as well as in relation to his or her gender, height, and environmental factors, ethnicity and race. Pulmonary dysfunction can be categorized into obstructive, restrictive and mixed pulmonary function changes, and different pulmonary function changes will correspond to the corresponding possible diseases. Firstly, restrictive ventilatory dysfunction is seen in thoracic deformities, congenital malformations of the lungs, excessive hypertrophy and hyperplasia of the pleura, and diffuse interstitial fibrosis. Secondly, mixed dysfunction is common in the presence of both obstructive and restrictive diseases, such as narrowing of the airways due to endobronchial tuberculosis with tuberculous pleurisy, and in silicosis and pneumoconiosis in combination with severe bronchial infections of the lungs. Obstructive ventilatory dysfunction is also seen in chronic obstructive emphysema and bronchial asthma.