Small nodules in the lungs may be caused by inflammation, tumor, tuberculosis and other reasons. 1. Inflammation: If the patient has inflammation in the lungs and repeated infections, it will stimulate the surrounding cells, which will form inflammatory nodules and make the patient’s lungs show the symptoms of small nodules. 2. Tumor: if the patient’s lungs have tumors, it will also lead to the appearance of small nodules in the lungs when the patient is examined, which may be caused by genetic factors, gene mutation, long-term smoking and other reasons. 3. Tuberculosis: If the patient has suffered from tuberculosis before, after anti-infection treatment, local scars will be left, which will make the patient’s lungs appear small nodules. Generally small nodules in the lungs will not affect the patient’s health, if the nodules appear to increase or malignant changes, you need to timely treatment through surgical resection.