Ground glass nodules are generally referred to as pulmonary ground glass nodules, which have well defined borders. Pulmonary ground glass nodules are cloudy density shadows with mildly increased density on CT. If the border of lung ground glass nodule is clear, most of them belong to benign lesions, which may be caused by inflammation or benign tumors, and can be combined with routine blood tests, sputum bacterial culture and other experiments to make clear. If the boundaries of pulmonary ground-glass nodules are vague, it is considered that they may be malignant lesions, which may invade the surrounding soft tissues and can be clarified through pathological examination. Benign lesions include lung inflammation, charcoal deposition, and fungal infection; malignant lesions include lung adenocarcinoma, squamous carcinoma, non-small cell lung cancer, and lung metastasis. Therefore, when lung ground-glass nodules appear, one should go to the hospital in time to find out the cause of the disease, and if necessary, carry out targeted treatment.