The ACTH stimulation test is occasionally used to test adrenal production of aldosterone at the same time as cortisol to also help in determining if primary (hyperreninemic) or secondary (hyporeninemic) hypoaldosteronism is present.[1] Human ACTH has a slight stimulatory effect on aldosterone,[19] but the amount of synthetic ACTH given in the stimulation is equivalent to more than a whole days production of natural ACTH, so the aldosterone response can be easily measured in blood serum.[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.