Vertebrobasilar insufficiency is a condition that occurs when there is reduced blood flow to the back part of the brain, which is supplied by the vertebral and basilar arteries. This can lead to symptoms such as dizziness, balance problems, and visual disturbances. It often results from atherosclerosis, where arteries become narrowed due to plaque buildup. Risk factors for vertebrobasilar insufficiency include high blood pressure, high cholesterol, and smoking. Diagnosis typically involves imaging tests like MRI or CT scans to assess blood flow and identify any blockages. Treatment may include lifestyle changes, medications, or surgical interventions to improve blood circulation.