Insufficient cerebral blood supply may be caused by cerebral arteriosclerosis, metabolic syndrome, cervical spondylosis and other reasons. 1. Cerebral arteriosclerosis: when plaques of different degrees form in the blood vessels in the brain, it may cause narrowing of blood vessels, affecting the normal flow of blood and leading to insufficient blood supply to the brain. 2. Metabolic syndrome: If the patient suffers from high blood sugar, high blood fat and other diseases, it may lead to increased blood viscosity, causing blood flow to slow down, resulting in insufficient blood supply to the brain. 3. Cervical spondylosis: If the cervical spine has been strained for a long time, osteophytes and herniated intervertebral discs occur, the vertebral arteries will be easily compressed and stimulated, which will affect the blood flow to the brain and lead to insufficient blood supply to the brain. Patients with insufficient blood supply to the brain should go to the hospital in time, and after clarifying the cause of the disease, give appropriate treatment and therapy under the guidance of the doctor.