The risk of malignancy is higher for ground-glass nodules than for solid nodules, but ground-glass nodules can also be the result of benign disease, so which is more serious depends on the specific benign or malignant nature of the nodule. Lung nodules can be categorized according to their density as pure ground-glass, solid, or mixed nodules. Mixed nodules have both a solid and a ground-glass component and are also known as partially solid or mixed ground-glass nodules, while both mixed and pure ground-glass nodules are ground-glass nodules. Ground glass nodules have about an 18% chance of being malignant in pure ground glass nodules, mixed nodules have about a 63% chance of being malignant, and solid nodules have a 7% chance of being malignant. The overall risk of malignancy was higher for ground glass nodules than for solid nodules. However, both ground glass nodules and solid nodules can be the result of malignant tumors such as lung cancer or benign conditions such as pneumonia or malignant tumors. The presence of either ground glass or solid nodules should be taken seriously and prompt medical attention is recommended to avoid delay.