Whether or not the growth of a lung nodule by 2 millimeters in 4 years is serious depends on the benign or malignant nature of the lung nodule. If the nodule is benign it is usually not serious, if it is malignant it is more serious. In addition, nodules are only imaging descriptions that do not determine the nature and cause of the disease, and the severity cannot be assessed based on the nodules alone. Lung nodule growth of 2 mm in 4 years, indicating that the rate of growth of the nodule is relatively slow, most of these cases are benign lesions, the impact on the body is not very large, but still need to cooperate with the doctor for follow-up, the need is to take measures to treat. In addition, there may be malignant nodules, whether or not the growth is more serious, once diagnosed should be taken as early as possible to take a comprehensive treatment based on surgery. It is important to note that the nodules are only a description of the imaging examination, which cannot determine the nature and cause of the disease, and the severity of the nodules cannot be assessed solely on the basis of the nodules, but also need to go to the hospital for professional examination to determine the nature of the nodules.