Patient risk factors for contrast side effects: 1. Poor renal function After contrast injection in general hospitalized patients, 5% may experience reversible renal impairment; however, in patients with pre-existing moderate to severe renal dysfunction, approximately 75% of them may have increased renal impairment after contrast injection. Diabetes mellitus, multiple myeloma and water loss are well known risk factors. 3, asthma The risk of severe and moderate reactions is 5 times and 7 times higher than normal, respectively. The risk of severe and moderate reactions is 2.3 times and 1.7 times higher than normal, respectively. 5.Urticaria The risk of severe and moderate reactions is 2 and 4.8 times higher than normal, respectively. 6.Eczema The risk of having a severe reaction is 4.8 times higher than normal. 7. Other allergic diseases The risk of severe and moderate reactions is 3.4 and 1.8 times higher than normal, respectively. History of other drug allergies 8. Heart disease The risk of death and severe reactions to various heart diseases are 8.5 and 4.5 times higher than normal, respectively. Among them, the risk of congestive heart failure, coronary heart disease and heart rhythm is greater. The risk of severe, moderate and mild reactions was 10.9, 8.7 and 6.9 times higher than normal, respectively. About 40% of people with a history of contrast allergy have side effects after re-injection of contrast media, but many of these reactions are mild and moderate. 10. History of other drug allergies The risk of severe and moderate reactions is 3.2 times and 2 times higher than normal, respectively. 11. Age factors The incidence of side effects is also higher in children under 1 year of age and in older people over 60 years of age, especially in cases of more severe disease.