Enhanced CT is generally not very harmful, but it depends on when and how often the enhanced CT is done. If the enhanced CT is done only once in a long time and the iodine contrast agent is used regularly, the harm to the human body is negligible. If you do repeated enhanced CT in a shorter period of time, the frequency of using iodine contrast agent is too high, leading to allergic reactions in the human body, such as skin allergies, commonly hives, and possible reactions such as low blood pressure and palpitations. Moreover, repeated enhancement CT, iodine contrast agent will affect the metabolic function of the liver and kidneys, causing more damage to the liver and kidneys. If the condition of renal insufficiency exists in itself, it will also aggravate the damage of liver and kidney functions. Therefore, people with allergies and renal insufficiency should be cautious of doing enhanced CT. before doing enhanced CT, be sure to communicate with your doctor in detail to understand the contraindications of enhanced CT examination.