The way to determine whether tinnitus is caused by cerebral blood supply insufficiency can be through the characteristics of medical history, clinical manifestations, and laboratory tests. 1. Characteristics of medical history: Tinnitus caused by insufficient cerebral blood supply is usually accompanied by cerebrovascular atherosclerosis or carotid vascular atherosclerosis. Therefore, tinnitus occurs in patients with long-term hypertension, diabetes mellitus, hyperlipidemia, smoking, alcohol consumption, obesity and other underlying medical history, can consider cerebral blood supply insufficiency. 2. Clinical manifestations: cerebral blood supply insufficiency is caused by ischemia of the posterior circulation, in addition to tinnitus, usually dizziness, darkness in front of the eyes, and tinnitus caused by the vestibular nerve is accompanied by vertigo and visual rotation, nausea and vomiting, which can be initially differentiated by symptoms. 3. Laboratory examination: patients with insufficient cerebral blood supply can see plaque formation in the arteries by doing cerebral vascular ultrasound and cervical vascular ultrasound, and abnormal increase in blood lipids, blood glucose and other atherosclerosis-causing indexes by taking blood tests. If arterial plaque formation and stenosis are not detected by vascular ultrasound, the possibility of posterior circulation ischemia is unlikely, and it is necessary to consider the tinnitus caused by other reasons. Therefore, to determine whether tinnitus is caused by cerebral blood supply insufficiency, it is necessary to comprehensively determine through the history, clinical manifestations and laboratory tests, tinnitus should be timely medical treatment to avoid delaying the condition.