Pulmonary nodules are single, well-defined nodules with a diameter less than or equal to 3 cm, surrounded by air-containing lung tissue, with a diameter of more than 3 cm falling within the range of pulmonary masses. Nodules have complex etiology and lack of specificity in clinical manifestations, so it is difficult for doctors to diagnose them. In general, the probability that an isolated lung nodule is a malignant tumor is about 20-40%, and the probability of malignancy increases significantly with age. What are the people who tend to be “favored” by lung nodules? 1.Long-term smokers; 2.History of tumor or family history; 3.People who have had lung diseases or injuries; 4.People who are exposed to harmful chemicals and those who are under high mental stress; 2.What are the symptoms of lung nodules? Patients with lung nodules often have no obvious symptoms and signs in the early stage, some patients may experience cough, coughing, hemoptysis, chest pain, etc. If there are obvious symptoms, the condition is more serious and it may be a sign of early lung cancer, which must be treated in time. If early stage lung cancer is treated timely, most people can survive for a long time with little recurrence and metastasis. C. Lung nodules are time bombs, always be alert to lung cancer The development of lung nodules from small to large and from benign to malignant lung cancer is a gradual process, from small benign nodules at the beginning to 2cm, 3cm, 5cm …. The tumor is getting bigger and bigger, the malignancy is getting higher and higher, and from the beginning, no abnormal physical discomfort is felt, this process is scary and hard to control. Nodules mutating into lung cancer has become the main factor of lung cancer etiology, and patients must pay high attention to it. Many patients are finally diagnosed with early stage of lung cancer and their prognosis is very satisfactory due to timely treatment. Nodules in the lung should not be taken lightly because nodules themselves are tumors. If not treated in time, nodules will slowly grow and gradually deteriorate, and it will be very dangerous when the disease develops to advanced stage. Therefore, if a nodule is detected in the lung, it must be examined and diagnosed as soon as possible to avoid deterioration of the condition and miss the best time for treatment.