Lung cancer accounts for the first place in terms of incidence and mortality, and has been the most important malignant tumor endangering human health for many years. The main reason for its high mortality rate is that patients have no special discomfort in the early stage or only non-specific discomfort that is ignored, and most of them are already in the advanced stage of the disease when diagnosed, which measures the time for effective treatment. Mr. Guo, a writer, has a busy work schedule and a smoking habit. In the past two years, he has had a cough intermittently, which he thought was caused by smoking, and sometimes he drinks more water and sometimes contains some throat lozenges, which slightly relieves the symptoms and is no longer a concern. In the past six months, he often felt a vague pain in his right shoulder, and initially thought that he was tired from working at a desk, so he found a massage therapist to carry out massage and physical therapy according to “cervical spondylosis” and “frozen shoulder”. After a period of treatment, the pain relief was not obvious. A hospital examination showed that there was a 7 cm diameter mass in Mr. Guo’s right lung, which was diagnosed as squamous lung cancer by pathological examination, and the cancer cells had eroded into the shoulder joint, which was advanced lung cancer. In clinical practice, it is very common that lung cancer is not detected at an early stage. According to relevant studies, more than 70% of lung cancer patients in China are already in the middle and late stages when first diagnosed, and lung cancer cannot be detected at an early stage because the human lung is an open organ, which is easily affected by external carcinogenic factors. However, coughing is the most common manifestation in daily life, so patients often ignore these common manifestations and it is not easy to be detected by general examination. By the time lung cancer is detected, it often causes some comorbidities, such as pneumonia, obstruction of bronchial tubes, or invasion of blood vessels and bloody sputum, and by then lung cancer is in the middle and late stage. In terms of treatment, the earlier lung cancer is diagnosed and the more timely the treatment, the better its prognosis will be. In medical science, lung cancer is divided into four stages according to the size of the primary tumor and the degree of spread and metastasis in the lung and adjacent organs, which are represented by stage I, stage II, stage III and stage IV respectively, and are also roughly expressed clinically as early, middle and late stages. If the lung tumor can be detected in stage I, through surgical treatment, the patient is likely to be cured and the 5-year survival rate can reach 70%~80%. Patients who undergo regular treatment and follow up regularly can fully live as healthy people. However, cases detected at stage I only account for approximately 20% of lung cancer patients in clinical practice. By stage II, the 5-year survival rate after treatment can also reach 50%. However, the 5-year survival rate for stage III or IV patients is less than 20%, and most patients survive no more than 2 years after detection. In recent years, the popularity of early lung cancer screening has significantly increased the detection rate of early lung cancer, and due to the vigorous promotion of smoking cessation, the overall mortality rate of lung cancer has significantly decreased in western countries, while in China, the overall incidence and mortality rate of lung cancer are still on the rise. Therefore, early detection and early treatment are the keys to improve lung cancer outcomes and reduce lung cancer-related mortality. One of the most effective means of early screening is to perform a low-dose spiral CT scan of the lung. This test can detect microscopic lesions in the lung, initially distinguish inflammation from tumor, and more accurately diagnose lung cancer at an early stage. It is also the most critical technique to achieve early diagnosis of lung cancer, and should be commonly promoted among people with high risk of lung cancer. For suspicious lesions detected by spiral CT, regular review and follow-up can also be performed, which can achieve the purpose of detecting early lung cancer as well as avoiding the damage caused by unnecessary lung surgery and other excessive treatments. At present, in many health check-ups, chest X-ray or chest x-ray is mostly used for lung examination. However, since X-ray is not sensitive enough for early diagnosis of lung cancer detection, and it is not easy to clearly distinguish whether it is inflammation or tumor, especially for some smaller lesion tissues, the resolution of X-ray is even worse, which is often easy to cause a missed diagnosis, so low-dose spiral CT examination should be performed. For those with high suspicion of lung cancer or obstructive pneumonia, fiberoptic bronchoscopy can be performed, and suspicious tissues can be collected for pathological examination. It can also be combined with blood sampling for tumor marker examination. In addition, it is generally believed that lung cancer seems to be the patent of men because more men smoke and smoking is the main and most direct cause of lung cancer. In fact, the trend of lung cancer in modern women is increasing faster than men. According to clinical data, there is not much difference in the incidence of lung cancer in middle-aged women compared with middle-aged men. Why is there a feminization trend of lung cancer? Apart from the fact that a few women smoke themselves, most women are affected by passive smoking and oil smoke. They are not non-smokers but inhale “second-hand smoke”. In addition, women have been cooking in the kitchen for a long time, and the high temperature of cooking fumes produces toxic fumes, which deteriorate the local environment. The widespread environmental degradation during industrialization is also a worrying cancer-promoting risk factor. As far as lung cancer is concerned, there is no absolute susceptible group. At present, medical experts summarize the high-risk groups of lung cancer according to the incidence of lung cancer in different populations: 1) long-term smokers and long-term passive smokers; 2) those who are frequently exposed to pollutants, such as traffic police, teachers who use a lot of chalk for a long time, those who are exposed to asbestos, ionizing radiation and microwave radiation at work; 3) those who have had lung diseases; 4) those who have a family history of tumors. These high-risk groups should undergo 1 low-dose spiral CT screening scan regularly every year. Once suspicious nodules and other lesions are detected, the interval between reviews should be shortened or more aggressive diagnostic and therapeutic measures should be taken in a timely manner if necessary, according to the guidelines set by the health professional.