Small subpleural nodules in both lungs refer to round or circular shadows of increased density in the subpleural area of both lungs seen on X-ray chest film or lung CT. If a lung infection is first suspected, the lung CT can be repeated after two weeks of anti-infection. If there is no change, the lung CT should be repeated periodically, for example, after three months, and if there is still no change, after six months, and if there is still no change, the follow-up interval should be decided under the guidance of the doctor. If, in the course of the follow-up, small nodules become larger, become unevenly dense, or develop vascular signs, vacuolar signs, lobar signs, pleural depression signs, etc., the diagnosis should be further confirmed as soon as possible for early treatment.