The causes of small nodules in the upper lobe of the right lung are as follows: a. Benign lesions: for example, because of air pollution, outside dust and particles are sucked into the lung, and over time an inflammatory reaction occurs inside the lung, which is engulfed and wrapped by inflammatory cells, such as macrophages, and nodules are formed. Patients with tuberculosis and pneumonia are not thoroughly treated in time, caused by the foci left behind. Second, malignant lesions: pulmonary nodules can also suggest a malignant lesion. Whether the cause of small nodules in the upper lobe of the right lung is specifically benign or malignant requires further observation and, under the guidance of a medical professional, further puncture or other tests to clarify the nature of the nodules.