Long-term untreated smog disease may cause transient ischemic attack, cerebral infarction, cerebral hemorrhage, epileptic seizures, and may even be life-threatening. 1. Transient ischemic attack: At the onset of the disease, patients will experience episodes of dizziness, headache, limb weakness and sensory impairment, which usually lasts for one hour or less. 2. Cerebral infarction: smog disease may cause cerebral infarction, patients may have slurred speech, limb motor and sensory dysfunction. 3. Cerebral hemorrhage: when the aneurysm ruptures and bleeds, it will lead to hemorrhage of the brain parenchyma, which will be manifested as limb motor and sensory dysfunction, seizure, consciousness disorder, etc., and even endanger the life. When you suffer from smog disease, you should go to the neurosurgery department of the hospital in time for treatment.