Insufficient blood supply to the brain refers to a localized blood supply deficiency in the human brain that causes brain dysfunction. The cause of cerebral insufficiency is related to cerebral atherosclerosis. Acute cerebral insufficiency (acute cerebral ischemia) is a common disease in the elderly and has received more clinical attention, while chronic cerebral insufficiency (CCCI) has received little attention. Normal brain function depends on proper cerebral blood flow. When the blood flow in brain tissue is lower than normal and does not cause brain cell death, the cerebral vasculature compensates for it by self-regulating function and increasing the oxygen intake and utilization of tissues to maintain normal blood flow and normal metabolism, and when this compensatory mechanism still cannot maintain normal blood flow and normal metabolism, it can cause brain dysfunction and clinical manifestations of cerebral hypoperfusion, such as feeling dizzy, dull and unclear, memory loss, and mental discomfort. The clinical manifestations of cerebral dysfunction, such as feeling dizzy, dull and unclear, memory loss, mental weakness, weakness, easy fatigue, anxiety, insomnia and a series of manifestations of brain function decline. If the brain tissue is in this low perfusion state for a long time or on a regular basis, it can also lead to structural damage and morphological abnormalities of the brain tissue. Histopathological changes of chronic cerebral hypoperfusion include cortical atrophy, cortical and hippocampal neuronal degeneration, white matter sparing, glial cell proliferation and capillary bed alterations. Several basic and clinical studies suggest that chronic cerebral hypoperfusion is a risk factor for subcortical atherosclerotic encephalopathy, vascular dementia, Alzheimer’s disease and cerebral infarction.