It’s like smoke and fog, what a mesmerizing mood! But when it appears on a medical image, you can’t help but be creeped out! This is the “smoke” formed during cerebral angiography in the brain, which looks light but is actually dangerous. The reason why it is dangerous is that once it strikes, it may manifest itself in different degrees of weakness of one limb or one side of the body, partial sensory impairment, aphasia, visual impairment of one eye, etc. In severe cases, brain hemorrhage or cerebral infarction may occur, resulting in hemiplegia, disability, and even life-threatening. What is this horrific smog disease? How long can you live once you have it? Smoker’s disease is a rare abnormal disease of the vascular network at the base of the brain, mainly due to chronic progressive stenosis or occlusion of the major bilateral branches of the cerebral arterial ring (the siphon section of the internal carotid artery and the anterior and middle cerebral arteries, and sometimes also the beginning of the posterior cerebral artery), followed by the appearance of a small vascular network with abnormal side branches. Because cerebral angiography shows many dense piles of small blood vessels, resembling the smoke exhaled during smoking, it is imaginatively called “smog disease”. The question of “how long can a patient live with smog disease” should not be considered with extreme pessimism, as it is related to age of onset, primary cause, severity of the disease, degree of brain tissue damage, and speed of progression. How long can a patient with smoky disease live, this life expectancy varies, some can live a lifetime without the onset of the disease, some may die at a very young age when intracranial hemorrhage occurs. The mortality rate of smog is about 7.5%, including 10% for adult patients and 4.3% for pediatric patients, and the main cause of death is intracranial hemorrhage. Once a patient is diagnosed with smog, he or she must be treated as soon as possible and not to think about how long a smog patient will live.