With the frequent occurrence of haze, lung cancer is also getting more and more attention. Lung cancer is the number one cancer in both developed countries and China, and not only the incidence of middle-aged people is increasing, but some young people and women are also detected. Currently, lung cancer is detected in two main ways: through physical examination and during respiratory outpatient visits. The most reliable medical examination for lung cancer is CT scan of the chest, but lung cancer is mainly detected through outpatient respiratory care. Less than 20% of patients are detected by physical examination. Therefore, it is necessary to have an annual CT scan of the chest so that the radiation dose is also safe. Smoking is an important factor leading to lung cancer The occurrence of lung cancer is mainly related to smoking, occupation (close exposure to asbestos, radon gas, mustard gas, polycyclic aromatic hydrocarbon compounds, chloromethyl ether, chromium, nickel, inorganic arsenic compounds and radiation, etc.), air pollution (polluted air contains a large amount of automobile exhaust and combustion waste) and other factors. Therefore, people who have such factors in their lives are good candidates for lung cancer. In recent years, experts have noticed a grim fact – the number of non-smokers with lung cancer is increasing, especially more common in women. Coinciding with this fact, the types of lung cancer have also changed considerably. The incidence of squamous lung cancer (occurring in the epithelial cells of the large airways), which is more related to smoking, has decreased, while adenocarcinoma of the lung (occurring in the secretory area of the lung), which is less related to smoking, has increased by 15%. Air pollution, indoor (upholstery and other chemicals) pollution, oil smoke, and secondhand smoke may be an important factor in lung cancer in non-smoking women. There are no obvious specific lung cancer symptoms in the early stage of lung cancer. Those who did not have cough in the past but cough recently and do not heal after more than two weeks of treatment, with blood in the sputum; elderly patients with chronic bronchitis who have cough for a long time but the sound or nature of cough has changed recently, all suggest the possibility of cancer. It is worth mentioning that some lung cancers do not start with respiratory symptoms such as cough, but first appear with symptoms other than respiratory tract, such as joint pain, frozen shoulder, etc. Five signs of suspected lung cancer 1. Cough Lung cancer has different symptoms due to its location and different functional damage. If the tumor grows on the bronchial tubes, it will easily produce cough due to strong irritation. However, the degree of coughing varies. About half of the patients have irritating choking cough, no sputum, a little white foamy sputum or blood in sputum. In secondary infections, yellow sputum is coughed up. People with pre-existing chronic coughs should be alerted if they notice a different nature of cough than usual. Patients with a high incidence of age should seek early medical attention if the cough is ineffective with treatment or persists for a longer period of time. Those who have a cough with blood should be alerted and seen early. Coughing up blood This is a special feature in early lung cancer cases, such as central lung cancer, coughing up blood often occurs in the early and middle stages of the disease, and the amount of blood is small, bright red in quality or mixed with foam. The reason for this phenomenon is that the tumor surface is rich in blood vessels. Coughing damages the surface layer and causes the blood vessels to rupture. If there is occasional coughing of more blood, it is often repeated or lasts for a longer period of time. 3.Fever When central type lung cancer grows to semi-obstruction or total obstruction in the bronchial lumen, it may produce obstructive pneumonia. The fever is usually around 38℃, which can be easily reduced by anti-inflammatory treatment. However, if the obstructive lesion is not removed, the pneumonia will reappear soon afterwards, forming recurrent pneumonia. 4, hoarseness Hoarseness is more common in laryngitis, colds and acute bronchitis, and can also occur after inappropriate vocalizations and excessive speech or even heavy smoking and drinking. However, this kind of hoarseness can usually be treated symptomatically or cured by rest. The hoarseness caused by lung cancer, thyroid cancer and laryngeal cancer is very different from the above type of hoarseness, especially lung cancer, and laryngoscopy should be performed for people with high risk of lung cancer. According to statistics, about 20%-30% of lung cancer patients can have hoarseness at different stages of the disease, including early stages, and among them, central lung cancer can be as high as 40%. The pathology of hoarseness caused by lung cancer is that the cancer invades and compresses the nerves that govern the vocal cords, and this hoarseness often occurs suddenly, progresses rapidly, or even completely loses voice. 5.No symptoms About 1/3 of lung cancer patients do not have any obvious early symptoms and can only rely on regular examination for early detection of their lesions. Early detection and early treatment to improve the cure rate of lung cancer For lung cancer patients, surgery is the first choice of treatment; at present, when lung cancer patients are first diagnosed in China, two-thirds of them already have distant metastasis and lose the chance of surgery. According to patients’ different stages of disease, different tissue types, different biological behaviors of tumors and systemic conditions, multidisciplinary consultation MDT is used to integrate surgery, radiotherapy, chemotherapy and other multidisciplinary treatment methods so as to achieve the best treatment effect. At present, surgery is the preferred treatment for lung cancer. Simply put, patients with non-small cell lung cancer can receive surgery after detailed examination, excluding distant metastases such as brain and bone, and if lung function is tolerated. For high-risk groups, low-dose CT screening can be considered annually. The importance of early detection is evident from the fact that early lung cancer patients do not need chemotherapy after surgery and have a five-year survival rate of 90%.