Sudden dizziness in the head may be caused by the following conditions: first, because there is a transient ischemic attack, because when there is transient cerebral ischemia, it will lead to a lack of energy and oxygen in the brain cells or nerves, thus causing the brain nerves and brain cells to be unable to perform and normally control the functions of the body’s activities, and also unable to timely control the body’s balance, movement and other comprehensive movements. In addition, sudden cerebral ischemia can lead to transient constriction of cerebral blood vessels, stimulating the nerves in the brain and causing dizziness; secondly, it may be due to blood pressure fluctuations, because when there are transient fluctuations in cerebral blood pressure, there will be sudden contraction and diastole of cerebral blood vessels, and in this process the cerebral blood vessels will be subject to certain trauma and stress, which can lead to thyroid hormones and norepinephrine in the body, etc. The rise in the content of these hormones causes a decrease in the level of metabolism, balance, and control of the brain, and also leads to a decrease in the information transmission function of the central nervous system, which can produce a feeling of dizziness.