Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.

[citation needed] Synthetic pharmaceutical drugs with corticosteroid-like effects are used in a variety of conditions, ranging from hematological neoplasms[3] to brain tumors or skin diseases.

[citation needed] Medical conditions treated with systemic corticosteroids:[2][4] Topical formulations are also available for the skin, eyes (uveitis), lungs (asthma), nose (rhinitis), and bowels.

[citation needed] Typical undesired effects of glucocorticoids present quite uniformly as drug-induced Cushing's syndrome.

A variety of steroid medications, from anti-allergy nasal sprays (Nasonex, Flonase) to topical skin creams, to eye drops (Tobradex), to prednisone have been implicated in the development of central serous retinopathy (CSR).

Both genes display some degree of polymorphic variation in humans, which may explain how some patients respond better to inhaled corticosteroid therapy than others.

[48] Tadeusz Reichstein, Edward Calvin Kendall, and Philip Showalter Hench were awarded the Nobel Prize for Physiology and Medicine in 1950 for their work on hormones of the adrenal cortex, which culminated in the isolation of cortisone.

[56] Lewis Sarett of Merck & Co. was the first to synthesize cortisone, using a 36-step process that started with deoxycholic acid, which was extracted from ox bile.

Russell Marker, at Syntex, discovered a much cheaper and more convenient starting material, diosgenin from wild Mexican yams.

[58] In 1952, D.H. Peterson and H.C. Murray of Upjohn developed a process that used Rhizopus mold to oxidize progesterone into a compound that was readily converted to cortisone.

[59] The ability to cheaply synthesize large quantities of cortisone from the diosgenin in yams resulted in a rapid drop in price to US$6 per gram[when?

[60] The exact nature of cortisone's anti-inflammatory action remained a mystery for years after, however, until the leukocyte adhesion cascade and the role of phospholipase A2 in the production of prostaglandins and leukotrienes was fully understood in the early 1980s.