Cardiography does not usually cause serious damage to the body, but occasionally patients may experience impaired kidney function, local hematoma, heart damage, etc. Coronary angiography is mainly used for coronary heart disease. With the improvement of technology and physicians’ level, the process of angiography is relatively simple, and the examination process will not cause serious damage to the body, but some patients may have some complications of the procedure. 1. Impaired renal function: mainly related to the damaging effects of contrast media on the kidneys, hydration can reduce the occurrence of renal damage. 2. Local hematoma: coronary angiography requires puncturing the arteries, the procedure may lead to local damage and local hematoma, most patients do not need special treatment, but a few patients may have serious hematoma. 3. Heart damage: The process of entering the catheter may lead to heart damage, such as heart perforation and induced arrhythmia. The coronary angiography process should be handled with care to avoid complications as much as possible, and should be adequately evaluated before the procedure, and it should be performed by a qualified physician.