A lung ground glass nodule that turns into a solid nodule is not necessarily cancer. A ground glass nodule is a description used during imaging. If the lung nodule has a relatively low density, the description of the CT exam is often used as a ground glass nodule. When a ground-glass nodule turns into a solid nodule, further pathologic examination is needed to clarify the nature of the nodule and to determine whether it is cancerous. In the early stage of lung cancer, the cancerous tissue is relatively small and low density, and the lung CT examination shows ground-glass nodules; with the passage of time, the nodules gradually increase in size, and the density of the nodules gradually strengthens, and at this time, the ground-glass nodules will become solid nodules, accompanied by unclear borders, and the peripheral edges are accompanied by burr signs. In this case, the nodule is cancerous. However, in some cases, the transformation of a ground-glass nodule into a solid nodule may be the result of the transformation of a benign lesion, such as an inflammatory disease of the lungs. During inflammation, the density of the lesion is relatively low and it appears as a ground-glass nodule. When the inflammation subsides, the lesion leaves behind fibrous streaks or fibrous spots, and then the ground-glass nodule becomes a solid nodule, but the boundary of the nodule is clear and there is no obvious increase in the size of the nodule. When the imaging examination found that the grinding glass nodules in the lungs are solid, pathological biopsy is needed to clarify the nature of the nodules and guide the clinical treatment.