Coronary angiography is generally painless, but some people may experience slight discomfort, such as pain from the anesthetic injection, as well as soreness and warmth after the injection of the contrast medium. Coronary angiography starts with local anesthesia on the outer arm or inner thigh, and the radial artery on the outer arm or the femoral artery on the inner thigh is chosen as the puncture point, which will cause slight pain due to the anesthesia of the skin, and then the contrast agent is injected here, which may also cause a feeling of soreness and swelling. After the contrast agent is injected into the body, some people may experience fever, and finally the coronary arteries are visualized. After the operation is completed, a hemostat is applied to the puncture site for 6 hours, which may cause soreness and swelling in the arm due to the long period of time in which the hemostat is applied. Coronary angiography is a minimally invasive cardiac test and is usually painless.