The time it takes to form a pulmonary nodule is not fixed and may take about six months or 1-2 years, or even longer. The time it takes for a pulmonary nodule to form can vary depending on the patient’s body type and there is no set time. There is no clinical significance to how long it takes for a lung nodule to form, and the most important thing to do to detect a nodule in the lung is to have dynamic follow-up. If the nodule is progressively larger, growing rapidly and with poorly defined borders, the patient needs to be alerted to the possibility of malignancy. In this case, the patient needs to undergo nodule resection surgery and postoperative pathological examination to clarify the nature of the nodule. If the lung nodule is growing slowly with clear margins and the patient has no clinical symptoms, most nodules are benign and are commonly associated with inflammatory pseudotumors, inflammation, etc. The patient can continue to be observed. It is recommended that adults have regular annual chest radiographs to achieve early detection and diagnosis of lung nodules, and then take timely and effective treatment.