Lung nodules 3 ~ 4 mm, generally belong to the lung micro-nodules, most of them are benign nodules, generally do not need to be treated, can be regularly observed, but there are still a small number of nodules are considered to be malignant, need to be closely and regularly follow up review. 1. In general, if the lung nodule is benign with 3~4mm, no special treatment is needed, but we need to pay attention to the regular review of lung CT, observation and treatment. In daily life, you should pay attention to regular and reasonable diet, quit smoking and drinking, and also strengthen exercise to improve your immunity. 2. If the tiny nodules in the lungs are 3~4 millimeters in size, and with the prolongation of time, the growth change occurs, accompanied by lobular, short burr, pleural pulling sign and other symptoms and characteristics, it is necessary to be alert to the early cancerous phenomenon of the nodules. Prompt consultation should be made and surgical resection should be performed if necessary. If the lung nodule is 3～4 millimeters in size, the patient should go to the hospital in time and follow the doctor’s instruction for examination to make a clear diagnosis.