CT examination will not cause significant harm to the body, only a very small number of people may experience discomfort, special groups such as children, the elderly or pregnant women, etc., should consult a doctor for specific advice. CT examination can be divided into ordinary CT and enhanced CT, CT examination will produce ionizing radiation, but the radiation dose is small, within the safe range, usually will not cause harm to the body, do not need to be overly alarmed. Enhanced CT requires intravenous injection of contrast medium, very few patients may have allergic reactions, such as skin rashes, shortness of breath and other allergic symptoms, it is recommended that patients who are allergic to iodine need to pay attention to inform the examining doctor before the examination to avoid allergic conditions. Children or older than 60 years old should assess the patient’s physical condition before CT, pregnant women CT examination may lead to fetal growth and development is affected, not recommended for pregnant women CT examination.