Lung hilar enlargement indicates that the shape and size of lung hilar are as usual, which can initially exclude the possibility of some diseases, mainly including parahilar lung cancer, lymph node metastasis, silicosis and pulmonary hypertension. 1. Para-portal lung cancer: If there are corresponding lesions, it will cause the formation of soft tissue mass next to the lung portals, which will lead to the enlargement of the lung portals. 2. Lymph node metastasis: If there is a metastatic tumor in the lymph nodes next to the hilum, the hilum will be enlarged and full. 3. Silicosis: the inhalation of the corresponding particles will cause the lymph nodes next to the lung hilum to enlarge and calcify, causing the enlargement of the lung hilum. 4. Pulmonary arterial hypertension: Abnormal conditions in the lungs can easily cause pulmonary arterial hypertension, which can further lead to thickening of the blood vessels next to the hilum, causing enlargement of the hilum. The possibility of the above diseases will be significantly reduced if the pulmonary hilum is not large, and further investigation needs to be combined with clinical symptoms and CT examination to make a comprehensive judgment. If the pulmonary hilum is not large but accompanied by obvious symptoms of coughing up blood, it is still necessary to consult a doctor for observation and standardized treatment under the guidance of the clinician, and it is important not to be negligent in order to avoid delays in the condition.