Clinical manifestations will be different in different parts of lung cancer recurrence. In case of intra-lung recurrence, it mainly includes cough, low-grade fever, chest distension and pain, blood in sputum and so on. 1. Cough: after treatment, cough symptoms of lung cancer patients will be obviously reduced. If there is recurrence of malignant tumor, it will lead to strong stimulation of respiratory tract and cause cough symptoms. 2. Low fever: lung cancer may cause low fever during the onset of disease, which will improve after treatment. If lung cancer recurs, the patient will have symptoms of low fever which will not go down, and in serious cases, high fever will occur. 3. Chest swelling and pain: Coughing caused by lung cancer recurrence may lead to different degrees of chest tightness, chest swelling and pain, etc. Some patients may have hidden pain in chest, and in serious cases, they may have breathlessness and other symptoms. 4. Blood in sputum: Due to the recurrence of lung cancer, the stimulation of malignant tumor or local infection may cause the patient to cough and rupture local capillaries, resulting in the symptom of blood in sputum. If metastasis occurs, such as recurrence in the brain, the patient may have headache, unsteady gait and other symptoms. If bone metastasis occurs, bone pain will occur. Lung cancer patients should be proactive in treatment, and if the above symptoms or other discomforts occur, they should go to the hospital in time to take correct measures for timely intervention.