Enhanced CT with contrast injection is not painful, but a few people may have an allergic reaction that causes some abnormal symptoms. Enhanced CT is a kind of CT examination, which usually requires the injection of contrast agent before the examination, which can show the diseased tissues more clearly and provide help in the diagnosis of diseases. When injecting the contrast agent, there may be no obvious discomfort and most people feel no pain. Some people may have hives after the injection of contrast medium, causing local skin redness, swelling, pain, sneezing, local pain aggravation and other uncomfortable symptoms. When this happens, you can drink plenty of water and take a rest after the examination to observe properly, and it will usually return to normal slowly. If the local discomfort continues to aggravate after injection of contrast medium during the enhanced CT examination, timely examination and treatment are necessary to avoid adverse consequences.