Small nodules in the right lower lung are usually round or round-like high-density shadows in the right lower lung that can be seen on X-ray chest films or lung CT. If the right lower lung nodule is caused by lung infection, it is usually reviewed after two weeks of anti-infection, and if there is no change, then it should be reviewed regularly, especially for patients over 40 years old, long-term smokers, those in second-hand smoke environment, and those with family history of malignant tumors. If the nodules become larger, or the density becomes uneven, and there are signs of pleural depression, vacuolation, vascular signs, lobulation, burr, etc., during the review process, it may be a malignant change, and further examination is necessary to confirm the diagnosis and treatment at an early stage.