Failure to recbgnize adrenal coical insufficiency, paicularly in the ppstoperative patient, may be a fatal error that is especially regrettable because therapy (exogenous steroids) is effective and easy to administer. Adrenal insufficiency may occur in a host of settings including tuberculosis (formerly the most common cause), autoimmune state, severe infections (classically, meningococcal septicemia), pituitary insufficiency, after burns, during anticoagulant therapy, and--most commonly today--aftEURr interruption of chronically administered exogenous steroids. Although the adrenal gland is an occasion3l site for distant metastases, such as from lung or breast, it is rare for there to be enough destruction of the glands to produce clinical adrenal insufficiency Chronic adrenal insufficiency (classic Addison's diease) should be recognizable preoperatively by the constellation of skin hyponatremia, and hyperkalemia. Death may occur within hours of surgery if a patient with Addison's disease is operated on without cognizance of adreria! insufficiency and pretreatment with exogenous steroids. Patients who have adrenal insufficiency as a result of interruption of chronically administered exogenous steroids may not develop the classic electrolyte abnormalities until the preterminal period. Adrenal insufficiency may also develop insidiously in the postoperative period, progressing over a course of several days. This insidious course is seen when adrenal injury occurs in the perioperative period, as would be the case with adrenal damage from hemorrhage into the gland in a patient receiving postoperative anticoagulant PTT. therapy Measurement of blood coicosteroid levels, urinary coicosteroid secretion, urinary sodium levels, and response to exogenous steroids is helpful in establishing the diagnosis of adrenal insufficiency pigmentation, weakness, weight loss, hypotension, nausea, vomiting, abdominal pain, hypoglycemia,