The causes of slow blood flow in the vertebrobasilar artery are mainly due to the following aspects: 1. There is a relationship with cerebral atherosclerosis, if the patient has diabetes, hypertension, hyperlipidemia, or long-term smoking and alcohol consumption, which can easily lead to sclerosis of the patient’s cerebral blood vessels, decreased elasticity of the blood vessels, and plaque formation, causing narrowing of the patient’s vascular lumen, which can easily lead to slow blood flow in the vertebral and basilar arteries, resulting in Patients develop cerebral blood supply deficiency. The vertebrobasilar artery is supplying blood to the posterior circulatory system, and patients will experience dizziness.2. The causes of slow blood flow in the vertebrobasilar artery are related to the high viscosity of the blood itself, such as primary thrombocythemia or true erythrocytosis, which can lead to slow blood flow, and patients will also experience slow blood flow in the vertebrobasilar artery.