Dexamethasone Suppression Test

Background

The dexamethasone suppression test (DST), low-dose DST, overnight DST, or 1-mg DST is a dynamic endocrine test in which hormone levels are evaluated based on the principles of biofeedback regulation. ^, A suppression test, in general, involves giving the patient a substance that would normally cause the inhibition of the release of the hormone. However, due to the excessive amounts of hormone or hyperfunction of the endocrine organ, a patient with the disease state would fail to have the hormone levels suppressed. A 48-hour, 2-mg DST can be used in certain populations that may have overactivation of the hypothalamic-pituitary-adrenal axis but without true Cushing’s syndrome. ^,