When dizziness occurs at the first sign of hunger, the most likely cause is a hypoglycemic reaction. In addition to the symptoms of dizziness, hypoglycemia is often accompanied by sweating, panic and general weakness. Brain tissue accounts for only 2%-3% of a person’s body weight, but the blood flow through the brain accounts for 20% of the heart beat output, and the oxygen consumption of brain tissue accounts for 20%-30% of the whole body’s oxygen consumption, so brain tissue can be said to be the most metabolically active organ in the body. Because there is almost no energy reserve in brain tissue, its energy mainly comes from the aerobic metabolism of sugar in blood, so brain tissue is very sensitive to ischemia and hypoxia. When hypoglycemia occurs, the energy metabolism demand of brain tissue is insufficient, brain cells will become hypoxic, and the brain electrical activity and brain cell function will be weakened, resulting in dizziness. If hypoglycemia is not corrected in time, brain cells become necrotic after hypoxia, and a large number of brain neurons undergo irreversible damage, which can lead to coma and even death.