Cortisol Deficiency
Cortisol deficiency can occur when the adrenal glands are not able to produce a sufficient amount of cortisol. This can be caused by the following: the pituitary gland is not able to produce the chemicals that are needed to be able to instruct the adrenal glands to produce cortisol; a condition known as congenital adrenal hyperplasia causes a blockage within the glands preventing the production of cortisol; the adrenal gland fails or becomes deficient; and a high level of steroids in the body can cause the glands to stop producing the hormone.

Congenital Adrenal Hyperplasia
A deficiency in cortisol can be controlled through replacement therapy with the intake of hydrocortisone tablets a number of times a day.