Adult fasting blood glucose concentration below 2.8mmol/L is called hypoglycemia.

Non-drug hypoglycemia includes starvation hypoglycemia, which is manifested as symptoms of the central nervous system and often occurs on an empty stomach or during exercise; Reactive hypoglycemia is characterized by adrenergic nerve excitation caused by eating. Compared with reactive hypoglycemia, the blood sugar level of starvation hypoglycemia is lower and lasts longer. Some hypoglycemia is mainly manifested in children or infants, while others mainly appear in adults.

Symptoms:

Hypoglycemia can be divided into two types: (1) Adrenal symptoms include sweating, nervousness, trembling, weakness, dizziness, palpitation and hunger, which are attributed to increased sympathetic nerve activity and increased adrenaline release (this can happen in patients undergoing adrenalectomy). (2) The manifestations of the central nervous system include confusion, abnormal behavior (which can be mistaken for drunkenness), visual impairment, stupor, coma and epilepsy. Hypoglycemic coma usually leads to hypothermia. Sympathetic symptoms cause the blood sugar to drop faster than central nervous symptoms, but the degree of hypoglycemia is light. No matter which type, there are obvious individual differences in blood sugar levels.