Cortisone: An adrenocorticoid hormone, a naturally occurring hormone made by and secreted by the adrenal cortex, the outer part (the cortex) of the adrenal gland.

Cortisone was the first of the "miracle drugs" for the treatment of rheumatoid arthritis. This historic feat was achieved by Edward C Kendall and Philip S. Hench at the Mayo Clinic in Rochester, Minnesota. Their discovery stemmed from the astute clinical observation that a woman with severe rheumatoid arthritis felt much better during pregnancy. They found what was responsible. It was a hormone from the outer part (the cortex) of the adrenal glands. They called it "cortisone." On Sept. 21, 1948, Hench gave a synthesized version of cortisone developed by Kendall to a patient with arthritis. Kendall and Hench shared the Nobel Prize in Physiology or Medicine in 1950 with Tadeus Reichstein from Switzerland "for their discoveries relating to the hormones of the adrenal cortex, their structure, and biological effects."

Synthetic cortisone acts after it is converted by the body (metabolized) to cortisol to exert its powerful antiinflammatory (and other) effects. Its many uses include the treatment of adrenocortical deficiency and conditions associated with inflammation.