How to detect lung cancer early? About one-third of early stage lung cancer patients have no symptoms; and some other patients, despite having mild early symptoms, are not taken seriously or misdiagnosed, thus delaying the disease. Therefore, to detect early lung cancer patients, in addition to the need for regular large-scale population screening, for those who are over 40 years old and have symptoms of unexplained chest pain, hemoptysis and sputum, which are ineffective after treatment; those who have recurrent inflammation in the same part of the lung, which is ineffective after active anti-inflammatory treatment; patients with pulmonary tuberculosis whose condition is stable after treatment and then suddenly the lesion recurs and worsens, a segment or lobe of the lung with Those who have inflammatory infiltration and localized emphysema or atelectasis should be highly alert and undergo further examination. What should be paid attention to in the prevention of lung cancer? 1. Do not smoke. Those who have already smoked should make efforts to quit smoking or smoke less, and non-smokers should pay attention to avoid inhaling “second-hand smoke”. 2.Improve environmental pollution and strengthen self-protection. Control air pollution, especially industrial exhaust and motor vehicle emissions, reduce the harmful substances in smoke, install exhaust gas purification devices, to avoid incomplete combustion. For some chemical plants, smelters and workers who manufacture mustard gas, personnel in chemical laboratories, miners in mines, workers with long-term exposure to silica dust, occupational groups who can inhale radioactive dust, and personnel who manufacture and use arsenic-containing pesticides should take the necessary measures for effective self-protection. It is best to install exhaust fans in the kitchen to reduce the hazards of cooking fumes to cooks and housewives. 3.Minimize the incidence of diseases such as tuberculosis and chronic inflammation of the lung, and actively treat these diseases, which can help reduce the incidence of lung cancer. 4. Conduct regular screening for people at high risk of lung cancer and always be alert to the warning signs and early symptoms of lung cancer.