The upper and lower respiratory tract infections are determined by physical examination and special tests. For example, in bronchitis, coarse breath sounds can be heard, and in pneumonia, medium and small vesicular sounds can be heard at obvious lesions, and they do not disappear or decrease with coughing and sputum. In addition, by taking X-rays or CT of both lungs, it can be clearly seen that the lung texture is thickened and blurred bilaterally in bronchitis, while in pneumonia it can be clearly seen that the lesions are patchy and dense. The upper respiratory tract can be clearly seen with varying degrees of congestion, edema, and even exudation of purulent secretions in the pharynx, nasal cavity, or tonsils.