In general, the radiation hazard will basically disappear about 3-6 months after the CT examination, but there are individual differences, and the specific disappearance time has a definite relationship with the examination site. Although the radiological examinations currently applied in medicine are within the safe range, there is still a certain radiation effect, which the body absorbs and metabolizes mainly through its own immune system. In general, the radiation effects of cranial CT examinations are relatively small, and the body can gradually recover after 3 months. In contrast, the radiation dose of chest and abdomen CT examinations is relatively larger, and the radiation effects will basically disappear after 6 months. In addition, the radiation dose of enhanced CT is relatively larger, and enhanced CT uses contrast agents, then the impact on the human body is also greater. After CT examination, it is recommended to drink more water and eat more fresh vegetables, fruits and other foods containing antioxidant substances, which can promote the body’s repair.