Double lung nodules are nodules that appear in both the right and left lobes of the patient’s lungs. The causes of this condition may be lung inflammation, tuberculosis and lung cancer. 1. Lung inflammation: when both lungs are infected by pathogens, lung nodules can be caused because inflammatory cells infiltrate the lung tissue. 2. Tuberculosis: When both lungs are infected by tuberculosis bacillus, diffuse, corn-like nodules appear on both sides of the lungs, and the patients usually have symptoms such as cough, hemoptysis and low fever. 3. Lung cancer: if nodules are found in both lungs during physical examination, and they are large in size, irregular in shape, with irregular edges, high density, and in the form of ground glass, these nodules may be primary lung cancer or metastatic lung cancer, and they need to be diagnosed clearly through pathologic examination. 4. Others: There are still a considerable number of bilateral lung micronodules and small nodules that are benign, which may be related to chronic inflammation, soot stimulation, lymph node hyperplasia in the lungs, vascular shadows and so on, and do not need special treatment. If bilateral lung nodules are detected during a physical examination, it is important to follow the advice of a medical professional to standardize the diagnosis and treatment, and to follow up and review the disease on a regular basis.