正常的葡萄糖代謝是維持生命所必需，我們身體裡有許多荷爾蒙與血糖恆定有關，如胰島素、昇糖素、腎上腺素、腎上腺類固醇，及生長激素。當發生低血糖時，首先胰島素濃度下降，接著昇糖素濃度上升，再來是腎上腺素分泌增加。腎上腺素也與低血糖的症狀有關。第一型的糖尿病病人，容易產生低血糖相關的自主神經失調，除了神經病變外，也和腎上腺素分泌不足和低血糖經驗有關，但若能避免發生低血糖，此功能失調部分是可逆的。

Normal glucose metabolism is essential for life. Hormones including insulin, glucagon, epinephrine, cortisol and growth hormone are responsible for blood glucose homeostasis in our body. In reaction to hypoglycemia, insulin secretion decreases first, followed by increase in glucagon and then epinephrine secretion. Excessive epinephrine action is also related to the symptoms of hypoglycemia. In patients with type I diabetes mellitus, hypoglycemia associated autonomic failure is not uncommonly recognized. The risk is associated with diabetic neuropathy, reduced epinephrine response and prior hypoglycemia events. Once hypoglycemia can be avoided, the defects can be partially reversed.