Patients lying down, and also up when dizziness, the main consideration of the following aspects of the cause: First, benign positional vertigo: also commonly known as otolithiasis, usually in the patient’s head or body position changes in the process of transient dizziness, accompanied by visual rotation, serious times will lead to nausea, vomiting, characterized by the performance of dizziness in the time will have nystagmus. Second, postural hypotension: it may be related to body position, because when people change their body position, if the blood pressure is not adjusted in time, the blood supply to the brain will be affected, which will lead to dizziness, and even the symptom of blackness in front of the eyes.