ACTH stimulation test

[5][6] This test is used to diagnose or exclude primary and secondary adrenal insufficiency, Addison's disease, and related conditions.

Stress and recently administered radioisotope scans[citation needed] can artificially increase levels and may invalidate test results.

Spironolactone, contraceptives, licorice, estrogen, androgen (including DHEA) and progesterone therapy may also affect both aldosterone and cortisol stimulation test results.

To stimulate aldosterone, consumption of salt should be reduced to a minimum, and foods high in sodium avoided for 24 hours prior to testing.

[12] Approximately 20 mL of heparinized venous blood is collected at 30 and 60 minutes after the synthetic ACTH injection to measure cortisol levels.

[15] Commonly reported reactions are nausea, anxious sweating, dizziness, itchy skin, redness and or swelling of injection site, palpitations (a fast or fluttering heart beat), and facial flushing (may also include arms and torso), but should disappear within a few hours.

[16] In Addison's disease, both the cortisol and aldosterone levels are low, and the cortisol will not rise during the cosyntropin stimulation test[citation needed] In secondary adrenal insufficiency, due to exogenous steroid administration suppressing pituitary production of ACTH or due to primary pituitary disorder causing insufficient ACTH production, the adrenal glands will atrophy over time and cortisol production will fall and patients will fail stimulation testing.

[20] Same as cortisol, aldosterone should double from a respectable base value (around 20 ng/dl, must fast salt 24 hours and sit upright for blood draw) in a healthy individual.

[citation needed] The aldosterone response in the ACTH stimulation test is blunted or absent in patients with primary adrenal insufficiency including Addison's disease.

Recent data showed that Synacthen test results can be used to predict future recovery of HPA axis function in patients with reversible causes of Adrenal Insufficiency.