Dizziness, weakness of limbs and sweating may be caused by hypoglycemia. When blood sugar is too low, the patient may cause hypoglycemic encephalopathy can cause brain hypoxia, and when the cerebellum and brainstem are hypoxic, the patient may show dizziness, balance disorder, ataxia, and may also show weakness of limbs. In the case of cerebral hypoxia, the patient may show blackness in front of the eyes, or may have unilateral limb sensory impairment or motor dysfunction. In case of severe hypoglycemia, it may also cause palpitations, chest tightness, shortness of breath and sweating in the patient. If the patient’s blood pressure is too low, the above symptoms may also occur. Severe hypotension may cause cerebral hypoperfusion, which may cause insufficient blood supply to the brain, and the patient may also manifest as cerebral hypoxia. Severe hypovolemia can also occur if the patient is severely hypovolemic, usually mostly caused by massive diarrhea and massive vomiting in the elderly. If the patient has heart disease, such as severe arrhythmia, it may cause a decrease in the pumping function of the heart, which can also cause ischemia and hypoxia in the brain.