The main side effects of coronary CT include allergic reactions, deterioration of renal function, effects of radiation, and contrast agent leakage. Coronary CT is still a very safe examination, for patients without contraindications to the use of standardized operation, the actual incidence of the above complications are very low. 1. Allergic reaction: Coronary CT examination requires injection of iodine-containing contrast medium, which may cause allergy. Therefore, patients who are allergic to iodine or seafood should be cautious, and a skin test should be done before the examination, and if it is positive, the examination cannot be done. 2. Deterioration of renal function: For some patients with renal dysfunction or other metabolic system diseases, the use of contrast media may lead to renal function damage, which may cause increased creatinine, oliguria or anuria. 3. Radiation effects: Coronary CT is a radioactive test, so it is not recommended for women with reproductive requirements to avoid radioactive damage. 4. Leakage of contrast medium: When injecting contrast medium during coronary CT examination, some of the contrast medium may leak out and spread through blood vessels and tissues, which may lead to skin damage or damage to blood vessels and nerves. Coronary CT examination has some side effects, so you need to follow the doctor’s instructions to avoid causing adverse reactions.