It is normal to see no enlarged lymph nodes in the hilum and mediastinum, indicating that the lymph nodes are normal and not enlarged, and no special treatment is needed. If there is a history of enlarged hilar and mediastinal lymph nodes, it means that the disease is in the recovery period, and the main diseases that can cause enlargement are inflammation of the lungs, tuberculosis, malignant tumors and other diseases. 1. Lung inflammation: such as bronchopneumonia, interstitial pneumonia, lobar pneumonia, etc., can lead to pulmonary and mediastinal lymph node enlargement, it is recommended to follow the doctor’s advice to continue to consolidate the treatment with medication. 2. Tuberculosis: Mycobacterium tuberculosis infection can cause hilar and mediastinal lymph node enlargement, it is recommended to observe regularly and follow the doctor’s prescription. 3. Malignant tumors: such as bronchial lung cancer, when metastasis occurs, it can be seen that the lymph nodes of hilar and mediastinal lymph nodes are enlarged, if no enlargement is found, it means that the cancer is in the early stage, and surgical treatment can be carried out to prolong the survival time. If abnormalities are found in the examination, it is recommended to consult a doctor in time for clear diagnosis and early treatment.