There is no strict data on how much the ground-glass nodules in the lungs can grow in a year. Generally speaking, malignant nodules grow faster, while benign nodules may not change much, or may multiply rapidly in a short period of time (e.g., within 2 weeks). 1. Benign nodules: Benign ground-glass nodules are usually caused by inflammation. If the inflammation progresses quickly, the body lacks resistance or is not treated effectively, the nodules may multiply rapidly in a very short time. However, more often than not, benign nodules are more stable and do not change much during regular review. 2. Malignant nodules: Some malignant ground-glass nodules grow rapidly over the course of a year and may range from a few millimeters to more than a dozen millimeters, and metastases to other organs may also occur. Close monitoring of the nodules is needed, and early surgical treatment is needed when malignancy is suspected. Different nature of ground glass nodules grow at different speeds, and it is recommended that they be reviewed regularly and treated surgically if necessary.