There is no fixed time for recovery of lung function after pulmonary hemorrhage, it may take 2 weeks~12 months, which needs to be determined according to different causes such as lung infection, tuberculosis and lung cancer. 1. Lung infection is a relatively common disease that can cause bleeding in the lungs. Bacteria or fungi can damage the mucous membranes of the trachea and bronchus, thus leading to bleeding, which can usually be controlled in 2~4 weeks, and full recovery usually takes more than 4 weeks, and more serious infections may take longer. 2. Tuberculosis, the treatment of tuberculosis usually takes 6 months, which is the standard treatment cycle, so the recovery period usually takes more than 6 months to restore lung function. 3. Lung cancer, in case of bleeding in the lungs caused by lung cancer, it will take a longer time. On one hand, there is no fixed treatment cycle, and the lung function may gradually deteriorate with the seriousness of the disease. On the other hand, even if surgery is performed at an early stage, a longer period of follow-up treatment and rehabilitation is needed, usually 6 to 12 months. The specific rehabilitation cycle needs to seek medical advice in time.