Smog is a clinically uncommon disease, and even many primary care hospitals do not report such cases. Indeed, as a rare disease, the incidence of smog is very low, and the general public does not know about this disease or has even heard of it. However, it is a very dangerous disease. Smog is the result of chronic narrowing or occlusion of the major arteries of the brain, which subsequently leads to abnormal changes in the vascular network at the base of the skull, giving it a smoky appearance, hence the name smog. The narrowing and occlusion of the main arteries can lead to cerebral ischemia, which can lead to cerebral infarction with terrible consequences; and the walls of the smoke-like vessels at the base of the skull are very thin and fragile, which can rupture at any time and cause cerebral hemorrhage, which is even more dangerous and has a very high rate of disability and death. Because of the threat of cerebral ischemia and cerebral hemorrhage, it can be said that patients with smoldering disease are in great danger at any time, so once diagnosed with smoldering disease, they should undergo surgery as soon as possible.