Some of the mechanisms by which corticosteroids act are by suppressing the immune system, preventing the narrowing of blood vessels, blocking the accumulation of fluid in tissues known as edema, and preventing over-proliferation of skin cells. Corticosteroids are needed to suppress the body’s immune system when the immune system attacks the body’s own healthy cells. Corticosteroids may also act by reducing the body’s ability to produce chemicals that stimulate the painful process of inflammation. Therefore, when used to treat musculoskeletal pain, corticosteroids can ease pain, reduce inflammation, and improve the mobility of the joint.
Addiction to cortisone was the subject of the 1956 motion picture, Bigger Than Life , produced by and starring James Mason . Though it was a box-office flop upon its initial release,  many modern critics hail it as a masterpiece and brilliant indictment of contemporary attitudes towards mental illness and addiction.  In 1963, Jean-Luc Godard named it one of the ten best American sound films ever made.  John F. Kennedy needed to regularly use corticosteroids such as cortisone as a treatment for Addison's disease .