Centralized lung cancer refers to lung cancer that grows near the opening of segmental bronchial tubes, relatively close to the hilum. The more common symptoms of central lung cancer are: a. Irritating cough. Because the cancer grows in the larger airway, it stimulates the airway and causes irritating cough. Second, bloody sputum. Bloody sputum is mainly because the tumor grows in the large airway, which is rich in blood transportation, and after local rupture, it causes blood in sputum or intermittent small amount of hemoptysis. Fever. Fever is usually caused by secondary lung infection caused by the obstruction of trachea and bronchus after the tumor grows. Shortness of breath. Shortness of breath is caused by pneumonia and atelectasis after the airway is obstructed by the cancer, resulting in reduction of lung volume and restriction of lung ventilation.