Dexamethasone Suppression Test

This test looks at how your pituitary and adrenal glands are working together. It does this by measuring your body's response to a medicine given. It is a test that looks for Cushing's syndrome, Cushing's disease, tumors of the adrenal gland, and also tests for mental depression and insufficient thyroid gland secretions (hypothyroidism).

PREPARATION FOR TEST

No preparation or fasting is necessary.

NORMAL FINDINGS

  • Prolonged method

  • Low dose: greater than 50% reduction of plasma cortisol and 17-hydroxycorticosteroid (17-OCHS) levels

  • High dose: 50% reduction of plasma cortisol and 17-OCHS levels

  • Rapid method

  • Normal: nearly 0 cortisol levels

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.