Generally speaking, the number of lung cancer in men is much higher than that in women due to smoking or some other reasons. Early symptoms of lung cancer in men are as follows: Firstly, low-grade fever for unknown reasons. It may be related to inflammation of lungs, and patients often have symptoms of inflammation and fever, which are often neglected or misdiagnosed. Secondly, symptoms of the respiratory tract, such as cough and sputum, often appear in the early stage of lung cancer. Some patients with chronic long-term cough should be alert to the chronic diseases of the respiratory system and should also prevent lung cancer. Again, prolonged chest pain, intermittent dull pain or stabbing pain are all symptoms of lung cancer. If the pain keeps deepening, it may indicate that the lung cancer is progressing. Lastly, there will be a feeling of tightness and shortness of breath. Normal lung function is affected by the presence of tumor. Difficulty and shortness of breath are easily manifested during exertion, which is most obvious in central type lung cancer. In addition to the above, some other symptoms, wandering joint pain, are very much like the history of arthritis, but they are often identified with the presence of lung cancer, which is called extrapulmonary symptoms. Usually the following categories of men are prone to lung cancer: 1. Lung auscultation, those who have limited rales, flutes, snoring sounds not changed by coughing. 2.Those who smoke for a long time and the cough changes and there is blood in sputum. 3.Limited increased lung texture or limited emphysema that cannot be explained by general bronchitis. 4.Repeated inflammatory changes in one part of the lung. 5.Sudden dry cough, choking cough for more than two weeks, and anti-inflammatory treatment is ineffective, or the original chronic cough suddenly changed in nature. 6.Sudden blood in sputum and intolerable chest pain without obvious explanation.