Lung cancer can be treated if detected early, but the following are some common symptoms of lung cancer which are easily ignored. 1. Cough: The most common self-reported symptom of lung cancer patients is cough, and about 60% of patients have this as the first symptom. It is mainly a dry cough with paroxysmal irritation and no sputum or only a small amount of white foamy sputum. Hemoptysis: This is a typical clinical manifestation of lung cancer patients, and also one of the common first symptoms. About 30% of patients have this symptom for the first time. It is usually sporadic with blood in the sputum or blood shreds. 3. Chest pain: It is a common symptom in early stage lung cancer patients, and 20%-30% of patients have this first symptom. Different parts of the tumor may produce different pains, such as irregular dull pain or hidden pain in the chest; chest pain with obvious pressure points; pain that worsens with breathing, coughing and changing position, etc. 4.Shortness of breath and difficulty in breathing in chest: often caused by multiple reasons. Many lung cancer patients have different degrees of chronic lung diseases, and the occurrence of lung cancer will lead to the aggravation of the original symptoms; in addition, if the tumor is located in large bronchial tubes, it can lead to their narrowing and obstruction, which will affect breathing, etc. 5.Fever: Lung cancer can cause obstructive pneumonia and fever, which can be relieved by antibiotic treatment in many patients; in addition, tumor itself can also cause cancer fever, which is often persistent and antibiotic treatment may be ineffective. 6.Weight loss: It is a common symptom and not necessarily a manifestation of advanced stage. 7.Other: lung cancer may cause syndrome with tumor, such as neuromuscular disease (myopathy syndrome, etc.), acanthosis nigricans, hypertrophic osteoarthropathy, endocrine changes (Cushing’s syndrome, carcinoid syndrome, etc.), etc.