Lung cancer can bleed and bleeding from lung cancer is a common manifestation of lung cancer, and in early stage lung cancer can manifest blood in sputum. Blood in sputum is an early manifestation of lung cancer that should be paid special attention, so once there is blood in sputum, it is necessary to go to hospital for examination and do imaging examination and bronchoscopy according to the doctor’s judgment. In addition, some advanced lung cancers, especially the central type lung cancer, grow near the large airways, especially when the blood vessels are invaded and necrosis and ischemia occur, which can cause hemoptysis with very large amount, or even hemoptysis and asphyxia. Therefore, bleeding is the most common manifestation of lung cancer.