There is no authoritative information on how often CT lungs should be done without radiation hazards. It is generally safer for healthy people to have it done 1~2 times a year, and for those who have an indication for the test to follow the doctor’s instructions and have it repeated on a regular basis. Lung CT is a common medical imaging technique. Currently, there is no authoritative information on how often CT lungs should be done without radiation hazards. Lung CT is not a routine medical examination program. Therefore, if the healthy people want to check the relevant lung examination, generally speaking, 1~2 times a year will not produce radiation hazards. For patients with pneumonia, emphysema, tuberculosis, lung cancer and other indications for lung CT, it is sufficient to follow the doctor’s instructions to review the CT examination of the lungs on time, and the doctor will decide the frequency and interval of the review according to the condition of the patient. In conclusion, lung CT examination has a certain radiation, do not frequent examination, in order to avoid adverse effects on health. If you feel unwell after a lung CT, you should go to the hospital in time.