The phenomenon of dizziness when sitting up mainly has the following causes: 1, postural hypotension, the body will redistribute blood after changing from lying to sitting, the blood supply below the plane of the heart will increase, while the blood supply to the brain is correspondingly reduced, which leads to hypotension and causes dizziness. This type of patient is mainly seen in the elderly, because the elderly are mostly accompanied by atherosclerosis, the vascular elasticity is poor, it is difficult to adapt to the sudden change in position, resulting in blood redistribution. 2, plant nervous disorders, patients with plant nervous disorders will cause dizziness due to reflex vagal excitation caused by the change in position, resulting in lower blood pressure. 3, low cranial pressure syndrome, mostly seen in cerebrospinal fluid leakage or repeated lumbar puncture Patients who have repeated lumbar puncture examinations may experience dizziness and headache after sitting up, and the symptoms improve after lying down.