You are treating a 37-year-old female patient whose signs and symptoms lead you to suspect she is suffering from an endocrine disorder. You order a series of tests to aid in your diagnosis. A basic metabolic panel showed elevated sodium of 111 mmol/L (normal range 135-145), potassium 4.5 mmol/L, chloride 78 mmol/L, bicarbonate 23 mmol/L, glucose 85 mg/dL, and creatinine 0.7 mg/dL. Further testing showed serum osmolality at 234 mOsm/kg (normal range 275-295) and urine sodium less than 20 mmol/L consistent with severe hypovolemic hyponatremia. A random cortisol level was less than 0.2 μg/dL. The plasma ACTH level was elevated at 882 pg/dL (normal range 5-27). These test results most likely indicate the patient is suffering from which of the following disorders?

Question

Quizplus · Accepted Answer

The patient has severe hyponatremia, low cortisol, and elevated ACTH, which are indicative of primary adrenal insufficiency, also known as Addison's disease.  Addison disease results from a primary failure of the adrenal cortex to synthesize and secrete glucocorticoid (cortisol) and mineralocorticoid (aldosterone) hormones resulting in metabolic disturbances. Electrolytes (sodium, potassium, chloride, and carbon dioxide) are measured to help detect and evaluate the severity of an existing electrolyte imbalance characteristic of Addison disease. With Addison disease, the sodium, chloride, and carbon dioxide levels are often low, while the potassium level may be very high. If the adrenal gland is either not functioning normally or not being stimulated by ACTH, then cortisol levels will be consistently low.

You Are Treating a 37-Year-Old Female Patient Whose Signs and Symptoms