An ACTH stimulation test is done to see if the adrenal glands − located on top of each kidney − are able to make the right amount of hormones called cortisol and aldosterone. These hormones help keep blood pressure and blood sugar normal, as well as maintain salt and water balance in the body.

The ACTH stimulation test is done by giving a medication called Cortrosyn and drawing blood levels of cortisol. Cortrosyn stimulates cortisol production. Cortrosyn is given in two different doses, either a low dose or high dose, depending on what your doctor orders.