Enhanced CT requires the injection of contrast medium, and the adverse reaction of enhanced CT mainly refers to the adverse reaction caused by the injection of contrast medium, which may cause allergic reaction, and the allergic reaction is divided into mild, moderate, and severe allergic reaction. Mild allergic reactions generally appear facial flushing, headache, nausea, mild vomiting, mild hives, etc. Generally, this situation will not last for a particularly long time, and the patient can be relieved in time after drinking more water and injecting dexamethasone. Severe allergic reaction is severe laryngeal edema, or bronchospasm, convulsions, coma, shock, etc., this situation is very serious, need to rescue treatment in time, the occurrence of severe allergic reaction is also uncommon. In addition, the enhanced CT contrast agent is metabolized by the kidneys, if the patient’s kidney function is poor, the contrast agent may aggravate the damage to the renal function, so patients with poor renal function need to be careful to do enhanced CT examination. After the enhanced CT examination, patients will be advised to drink more water, which is conducive to the rapid elimination of contrast media from the body.