Corticosteroids are similar to cortisol, a hormone produced by the adrenal glands in the body. Cortisol is one of the body's own natural steroids. Cortisol is essential for life and well being. During stress, our bodies produce extra cortisol to keep us from becoming very sick. Normally the adrenal glands release cortisol into the blood stream every morning. The brain monitors this amount and regulates the adrenal function. It cannot tell the difference between its own natural cortisone and that of steroid medicines. Therefore, when a person takes high doses of steroids over a long time, the brain may decrease or stop cortisol production. This is called adrenal suppression. Healthcare providers generally decrease a steroid dosage slowly to allow the adrenal gland to recover and produce cortisol at a normal level again. If you have been on steroids long-term do not stop taking them suddenly. Follow your doctor's prescription.