Lung cancer does not have any special symptoms in early stage, but only symptoms common to general respiratory system diseases, such as cough, sputum and blood, low fever, chest pain and tightness, which can be easily ignored. The specific manifestations of early common symptoms of lung cancer are as follows: 1. Cough: Lung cancer usually produces irritating cough due to its growth on bronchopulmonary tissues and respiratory tract irritation. 2.Low fever: Obstructive lung lobes often exist after tumor blocks the bronchus, and the degree varies, with only low fever in mild cases and high fever in severe cases, which may temporarily improve after medication, but will recur soon. 3. Chest distension and pain: Early stage of lung cancer has mild chest pain, mainly manifested as boring pain, hidden pain, the location is not certain, and the relationship with breathing is also uncertain. If the distending pain continues to occur, it indicates that the cancer may involve the pleura. 4. Sputum blood: When tumor inflammation causes necrosis and capillary breakage, there will be a small amount of bleeding, which is often mixed with sputum and appears intermittently or intermittently. Many patients with lung cancer are diagnosed with sputum and blood. Early extra-pulmonary manifestations are as follows: 1. Bone and joint symptoms: these symptoms are more common. Since lung cancer cells can produce certain special endocrine hormones (heterogenous hormones), antigens and enzymes, these substances can operate on bone and joint parts, resulting in swelling and pain of bone and joint, often involving tibia, fibula, ulna, radius and other bones and joints, and the ends of fingers and toes are often enlarged in the form of pestle-like fingers. 2.Shoulder and back pain: lung cancer of peripheral lung type often develops posteriorly, erodes the pleura and involves the ribs and chest wall tissues, thus causing shoulder and back pain. Such patients rarely have respiratory symptoms. 3. Hoarseness: lung cancer metastases compress the laryngeal nerve, which may cause hoarseness due to vocal cord veneer paralysis. Since metastases of lung cancer can appear at an early stage and county metastases can sometimes grow faster than the primary ones, the clinical manifestations of metastases can appear before the primary ones.