Insufficient blood supply to the brain is usually not detected by CT, and cranial MRI can show foci of ischemia in the brain. The diagnosis of cerebral insufficiency is mainly based on clinical manifestations. Patients can present with signs and symptoms of cerebral hemispheric ischemia. For example, patients can show episodes of limb weakness, sensory abnormalities and speech dysfunction; patients can also show signs and symptoms of cerebellar and brainstem ischemia, such as dizziness, nausea, vomiting, dysphagia, choking on water; ataxia and dysarthria, diplopia, etc. Cerebral insufficiency is a clinical manifestation, not a disease, and is mainly seen in patients with cerebral atherosclerosis. The main risk factors causing cerebral arteriosclerosis include hypertension, hyperlipidemia and hyperglycemia. Therefore, patients with cerebral insufficiency of blood supply should actively control the risk factors of cerebral arteriosclerosis to prevent cerebral infarction caused by severe cerebral insufficiency of blood supply.