Angiography can be done for occlusion of one side of the carotid artery. The carotid artery is an important blood vessel supplying the brain, and there are more causes of carotid artery occlusion, such as atherosclerosis, arterial entrapment, and vasculitis. Clinical manifestations vary greatly and can manifest as dizziness, blindness, fainting, coma and so on. A definitive diagnosis can usually be made by cervical vascular ultrasound, cranial MRA, head and neck vascular CTA and angiography. Angiography is an interventional test that can clarify whether there is any stenosis, the degree of stenosis, whether it is occluded, and whether there is collateral circulation. However, angiography is an invasive test and may cause some adverse reactions, so not everyone can have angiography. If you are diagnosed with occlusion of one side of the carotid artery, you can undergo angiography according to your doctor’s recommendation.