Central lung cancer refers to tumors growing in the hilum and mediastinum. The common clinical manifestations are as follows: 1. dyspnea: due to the tumor pressing the airway, causing insufficient ventilation and symptoms such as dyspnea, chest tightness and breathlessness; 2. cough: due to the tumor cells eroding the blood vessels in the lung, causing irritating cough and sputum, and in severe cases, hemoptysis may occur; 3. fever: due to the tumor growth pressing the airway causing distal obstruction, resulting in poor drainage of sputum and airway secretions and pneumonia.