What kind of effect CT has on the body is related to the type of CT that the patient has. For example, if a patient has a CT scan, then there is only a certain amount of radiation to the body, but this amount of radiation is relatively small, and if it is within the scope of the medical examination, then there is not much effect on the body, because the amount of radiation is much lower than the national regulations of the safety range. If what the patient is having is an enhanced CT, since the patient has to be injected with the contrast agent, it is possible for the patient to have an allergic reaction to the contrast agent. Mild patients may experience flushing of the face, nausea, vomiting as well as hives, etc., but moderately severe patients may experience itching of the throat, numbness of the lips, breathing difficulties, dizziness, cyanosis and even a drop in blood pressure, etc., and the examination has to be stopped immediately.