Recently, "every additional CT scan increases the risk of cancer by 43%" has become a hot topic of public concern. Does doing CT pose a risk of cancer to the human body? Where does this sentence come from? On March 12th, Shi Jingyun, the director of the radiology department at Shanghai Pulmonary Hospital, stated in a media interview that this statement originated from a study published in Nature Medicine targeting children and adolescents. Shi Jingyun believes that this does not mean that doing CT will lead to cancer, because as long as the total radiation received is within a safe range, it can be considered safe and will not cause additional harm to the human body. (March 13th, Pengpai News) If we only understand it literally, readers may fall into a digital trap, thinking that since having an additional CT scan increases the risk of cancer by 43%, then having a few more CT scans would bring the risk of cancer closer to 100%. In situations where there is a fear of cancer, this statement will attract more attention, and some people may even believe it to be true. In fact, the truth is far from that. Cancer risk and cancer rate are two different concepts, and if they are confused, it is easy to be misled by this statement. An increase of 43% in cancer incidence is frightening, but a 43% increase in cancer risk is not worth worrying too much. Cancer is the result of a combination of multiple factors, and the risk of a single behavior is usually at a very low level, perhaps only measured in tens of thousands. Assuming that the risk of cancer for a single behavior is one in ten thousand, even if the risk increases tenfold, there is still one in ten thousand. It can be seen that having a CT scan increases the risk of cancer by 43%, which may sound scary, but its impact on an individual's health is limited. Radiation is harmful to the human body, but it also requires scientific analysis based on dosage. According to a report by the International Committee on Radiation Protection (ICRP), no increase in tumor incidence was observed when the radiation dose was below 100mSv, which means that 100mSv is a threshold that daily medical radiation examinations cannot reach, and the likelihood of cancer incidence is low. That is to say, when it comes to CT examination, the risk of cancer cannot be discussed without considering the radiation dose. If both the total radiation dose and the single radiation dose are within the safe range, CT examination is safe. Moreover, there is radiation everywhere in life, such as electromagnetic radiation generated by mobile phones and computer screens, and cosmic radiation from flying at high altitudes. The small amount of radiation generated by one or two X-ray and CT examinations a year has almost no impact on human health. From another perspective, any risk of cancer should be taken seriously and avoided as much as possible. Currently, excessive examination is still quite common in some hospitals. Not only are there cases of CT scans being performed beyond the indications, but there are also examination institutions that incorporate CT scans into routine examinations and promote them as universal examination items. From a professional perspective, only by strictly following the indications for CT examination and controlling the number of examinations as much as possible is the correct approach. Promoting mutual recognition of test results has been a key focus of healthcare reform in recent years. CT examination is more expensive and has a certain level of radiation, so it is even more important to reduce the number of repeated examinations, and should be considered as