Sudden dizziness and inability to stand may be related to physiological factors, or may be caused by low blood sugar, postural hypotension, benign paroxysmal positional vertigo, stroke and other reasons. 1. Physiological factors: If you have stayed up too late in the recent past, or the quality of your sleep is not good, resulting in insufficient sleep, the brain does not get enough rest for a long time, which will easily cause brain dysfunction, and you will show sudden dizziness, unable to stand up, and may be accompanied by headache, fatigue and other manifestations, which can be relieved after resting. 2. Pathological factors (1) Hypoglycemia: When hypoglycemia occurs, it cannot provide the necessary energy to the various systems of the body, resulting in insufficient blood supply and oxygen supply to the brain, which may cause sudden dizziness, inability to stand up, accompanied by cold sweats, weakness and other manifestations. (2) Postural hypotension: usually due to a sudden and rapid rise from a squatting or recumbent position, the blood in the whole body cannot be redistributed in time, which may easily induce postural hypotension, and dizziness and inability to stand may occur. (3) Benign paroxysmal positional vertigo: vertigo occurs when the position of the patient’s head changes, such as when getting up or lying down, and is usually accompanied by nausea, vomiting, sweating and other symptoms. (4) Stroke: Infarction or hemorrhage in the cerebellum may be manifested as sudden dizziness and inability to stand, which may be accompanied by nausea and vomiting, ataxia and other symptoms. Sudden dizziness can also be caused by other reasons. It is recommended to consult a doctor as soon as possible to clarify the cause and then give targeted treatment and conditioning.