The hazards of doing cardiography to the body include allergy, contrast nephropathy, and radial artery injury. 1. Allergy: when performing cardiography, contrast medium is needed, and some patients are allergic to contrast medium, and may even suffer from anaphylaxis. 2. Contrast nephropathy: mainly manifested as a significant increase in blood creatinine after the contrast examination, commonly seen in some elderly patients, this type of patients can be hydrated before the examination, thus reducing the incidence. 3. Radial artery injury: cardiography requires puncture from the radial artery, a small number of patients in the process may cause radial artery injury, mainly manifested as subcutaneous bruising, hematoma, most of which can be absorbed on their own. The above hazards do not occur in everyone. Whether or not to perform an imaging test should be evaluated by a professional doctor and decided by a professional doctor.