Sometimes the patient’s head suddenly dizzy, mainly consider the following aspects of the cause: 1, if the patient is in a long squat suddenly get up in the process of transient dizziness, to consider is caused by postural hypotension; 2, patients who often appear dizzy symptoms, if accompanied by head swelling, to consider is caused by high blood pressure, generally seen in patients with hypertension irregular taking antihypertensive drugs, blood pressure fluctuations are relatively large, easy to appear dizzy symptoms; 3, patients occasionally suddenly dizzy head, to consider is the cerebral arteriosclerosis, cerebral blood supply is insufficient to cause. Patients with occasional sudden dizziness should be considered to be caused by cerebral arteriosclerosis and inadequate blood supply to the brain, which are usually prone to sudden dizziness under exertion, mental tension and poor sleep, and can be clarified by doing transcranial Doppler examination; 4. Patients who stare at electronic screens for too long may also suddenly experience dizziness.