If a ground glass nodule is found in the lung on a CT image during a physical examination, don’t worry too much first, it can be considered not very serious, or at least much less dangerous than the presence of a solid nodular mass. Since CT is a thin scan, 1-1.5mm CT machines have been used in many hospitals, and in this case many nodules below 4mm may be found, regardless of whether they are small nodules or ground glass shadows, the vast majority of such nodules are benign, and the doubling time is very long, and it may take more than 400 or even 800 days for its size to grow and double. They are generally considered benign in medical terms. I hope you don’t get too nervous, because there are international and domestic guidelines on the follow-up and regular observation of occasional small nodules, and according to the guidelines, nodules smaller than 4mm can be observed without close observation, and only regular medical checkups are needed, including those below 6mm, a CT once a year is enough. So don’t be too nervous and very aggressive to see the doctor everywhere, it is not necessary to do a CT in every hospital.