腎上腺皮質素的生理功能包括：幫助維持血壓及心臟血管功能、調節免疫發炎反應、與調節蛋白質、醣類及脂肪之新陳代謝。糖皮質素使用在許多內科的疾病，如：自體免疫疾病、腎上腺皮質功能不全、各種過敏症、無防禦性休克 ( 或稱過敏性休克anaphylacticshock)、與器官移植等。糖皮質素藥物在某些急症治療也扮演著重要的輔助角色。腎上腺危象 (adrenal crisis) 多是潛在慢性腎上腺皮質功能不全，突然受壓力，急性代償失能所致。防治上首重辨識高風險的潛在慢性腎上腺皮質功能不全患者，及時給予糖皮質素治療是主要救命手段。高風險的病患在懷疑或預期腎上腺危象即將發生，即直接首日給藥hydrocortisone200–300毫克，必要時再加50 微克之fludrocortisone。而後每日以不超過50%減量，漸漸減劑量，之後並改為口服劑型治療。敗血性休克是最常被聯想到重大疾病相關的皮質功能不全 (critical-illness-related corticosteroid insufficiency, CIRCI) 的急症。敗血症常並存著CIRCI 的
狀況，此時低劑量糖皮質素是一種有效的輔助治療。重點在如何及時診斷與及時治療。雖然目前仍然沒有公認之診斷標準，但是治療上有些共識可作為臨床急症救助之參考。 近年來以中低劑量糖皮質素對急性呼吸窘迫症為輔助治療的研究結果一致顯示：早期與持續使用糖皮質素( 如methylprednisolone) 為有效的輔助治療。研究結果也顯示管控糖皮質素的副作用與防範炎症反彈，也是糖皮質素能發揮輔助治療成功的關鍵。2008 年American College of Critical
Care Medicine 的共識聲明中，建議以ACTH刺激試驗後血清皮質醇值最大增量< 9 μg/dL或血
清皮質醇基礎值小於10 μg/dL診斷為CIRCI。治療上建議對依賴血管加壓劑之敗血性休克治療，可以hydrocortisone 劑量為200 毫克/ 天，分成四個分劑量靜脈給予，或作為連續靜脈注
的劑量為240 毫克/ 天（10毫克/ 小時）為期至少7 天。建議早期急性重症呼吸窘迫症患者，以methylprednisolone 1mg/kg/day 早期介入，並連續給予14 天以上劑量。不dexamethasone 則不被建議使用的。

The physiological functions of adrenal corticoids include helping to maintain blood pressure and cardiovascular function, modulating immune inflammatory response, and regulating metabolism of protein,carbohydrate, and fat. Glucocorticoids are used in autoimmune disease, adrenal insufficiency, allergies,anaphylaxis, and organ transplantation.
Glucocorticoids also play an important role in acute illness.Adrenal crisis is a life-threatening critical condition. Once the diagnosis is suspected, treatment with large volumes of glucose/saline solution and glucocorticoid should be initiated immediately. Hydrocortisone 200-300 mg can be given on the first day, if necessary, together with 50 μg of fludrocortisone. The dose can be gradually reduced thereafter, and
then changed to oral forms.Septic shock is the most commonly associated with critical-illness-related corticosteroid insufficiency (CIRCI).But although the diagnostic criteria for CIRCI is still not well established, there is some consensus on glucocorticoid therapy for critical illness. Early and continuous use of glucocorticoid is an effective adjuvant therapy for acute respiratory distress syndrome (ARDS). Monitoring the side effects of glucocorticoid and preventing the rebound of inflammation are important factors for a successful therapy.American College of Critical Care Medicine consensus statement (2008) recommended that (1) Hydrocortisone in a dose of 200 mg/day in four divided doses or as a continuous infusion in a dose of 240 mg/day (10 mg/hr) for greater than 7 days is recommended for septic shock. (2) Methylprednisolone in a dose of 1 mg/kg/day for greater than 14 days is recommended in patients with severe early ARDS. (3) Dexamethasone is not recommended for the treatment of CIRCI.