Small nodules in the lungs are nodules less than 5mm in diameter found by medical imaging through lung examination, which are mostly related to certain infections, smoking, dust stimulation, or early stage of tumors. 1. Infectious factors: clinically, some tuberculosis infection, fungal infection, chronic inflammation stimulation can appear in the lung nodules, for acute infections, the symptoms are obvious, need to be given according to the specific circumstances of the relevant treatment. 2. Smoking or dust stimulation: long-term heavy smoking, or environmental pollution often contact with the dust crowd, some dust particles and harmful substances tend to stimulate the lungs lead to tissue fibrosis, the formation of lung nodules. 3. Benign and malignant tumors: common in patients with a history of smoking, family history of tumors. Lung nodules may be benign tumors or early stage of malignant tumors, which need regular review. For nodules with no change, consider them benign and do not need to be treated. For nodules with obvious morphological changes or rapid growth, it is necessary to give bronchoscopy or lung puncture to clarify the nature of the nodule, give surgical resection, and malignant tumors need to be combined with radiotherapy and so on. Lung nodules can also be seen in hyperplastic lymph nodes and nodal disease. If you find small nodules in the lungs, you need to have regular checkups and eat more fresh fruits and vegetables, avoid smoking and exposure to harmful gases, open the windows often for ventilation, and exercise appropriately to improve immunity and prevent lung diseases.