Micro nodules in both lungs may be pulmonary manifestations caused by chronic inflammation, autoimmune diseases, Mycobacterium tuberculosis infections, etc. 1. Chronic inflammation: chronic inflammation caused by long-term foreign body stimulation, such as long-term smoking, exposure to dust, animal breeding, etc.. It may also be related to old lesions left over from previous infections. 2. Autoimmune diseases: such as rheumatoid arthritis, single or multiple nodules can appear in the lungs, for the performance of rheumatoid nodules in the lungs. 3. Mycobacterium tuberculosis infection: tuberculosis is polymorphic on intra-lung imaging. Millet tuberculosis can be manifested as diffuse microscopic nodules in both lungs, accompanied by fever, night sweats and other clinical manifestations. If you find small nodules in both lungs, it is recommended to consult a doctor in time, complete the examination under the guidance of the doctor to clarify the cause of the disease, and follow the doctor’s instructions to actively treat or follow up regularly.