If you have a cough with weight loss, you should not ignore it as it may be a symptom of lung cancer. The incidence group of lung cancer is mainly concentrated in middle-aged and elderly people, because there are no obvious pre-symptoms, so once the disease is detected, it has already reached the middle and late stage, especially for people over 40 years old, especially those who have a long smoking history, they should seek detailed medical examination in time if they find the following conditions. What are the symptoms of lung cancer in middle-aged and elderly people? Unexplained blood in sputum or occasional small amount of hemoptysis, which has been excluded from bleeding diseases of nasal cavity, pharynx and esophagus. III. Frequent choking cough without improvement with antibiotics in those with pre-existing chronic bronchitis and emphysema, with sudden onset of cough aggravation and hemoptysis. IV. Unexplained cough with weight loss. V. Coughing, coughing and blood in sputum are found again after years of recovery from tuberculosis, but lacking the positive features of tuberculosis. When you go to the hospital with the above conditions, the doctor will take a detailed medical history, perform a thorough physical examination and do the necessary laboratory tests. For example, chest photo, chest tomography, sputum examination to find cancer cells, fiberoptic bronchoscopy, etc. If lung cancer is detected early, diagnosed and operated in time, it can achieve the purpose of restoring health.