Excessive blood flow in the head vessels on Doppler examination may be due to stenosis or occlusion of blood vessels, local vascular tortuosity, vasospasm, etc. It is recommended to analyze the results of specific examinations after consultation. 1. Stenosis or occlusion of blood vessels: If the blood vessels in the brain are narrowed or occluded due to atherosclerosis, an increase in blood flow rate may occur. Generally speaking, the increase in systolic blood flow rate is the most intuitive, and the average blood flow rate is more specific for diagnosing localized stenosis of blood vessels. However, when the stenosis is extremely severe and the stenotic segment is too long, there may be no increase in blood flow velocity. 2. Localized tortuous vessels: During Doppler examination, the tortuous part of the vessel may also show increased blood flow velocity, which should be carefully identified. 3. Vasospasm: When the cerebral blood vessels are stimulated by blood, mechanical stimulation, inflammation, emotional excitement and other stimuli, local cerebral vasospasm will occur, and the blood flow rate will increase rapidly. If the Doppler examination of blood flow in the head blood vessels is too fast, we should consult the doctor in time to find out the cause.