The sudden appearance of dizziness for a short period of time, only a second or so, leads to more causes of this symptom, the common ones are postural hypotension, hypoglycemia, cerebral blood supply deficiency, benign positional vertigo, etc. If the symptoms recur, it is recommended to promptly go to the local hospital for blood pressure, blood sugar, cranial CT, vestibular function and other examinations to clarify the cause. 1, postural hypotension: the performance caused by the change of blood pressure when the position changes. For example, if you suddenly stand up after a long squat, you will have a transient low blood pressure, accompanied by dizziness, unsteadiness, blurred vision and other symptoms, which can be relieved by itself in most cases, and in severe cases, syncope may occur; 2, hypoglycemia: when hypoglycemia attacks, the brain cells lack energy supply, resulting in sympathetic hyperexcitation and brain dysfunction, which can cause patients to have transient dizziness, accompanied by panic, sweating, hand shaking The symptoms usually improve quickly after eating; 3. Insufficient cerebral blood supply: It mainly refers to the insufficient blood supply to a certain part of the brain, which causes brain dysfunction and leads to recurrent dizziness, dizziness, headache and other symptoms; 4. It can be relieved soon after changing the posture. 5. Others: For example, vasospasm in the inner ear or vestibule, cervical spondylosis, overexertion, etc. can also cause patients to have transient dizziness.