Corticosteroid medications mimic the effects of the hormones that the adrenal glands on top of the kidneys produce, explains Mayo Clinic. They help suppress inflammation and the immune system, making them useful for treating conditions related to swelling and autoimmune disorders. Oral corticosteroid medications are often prescribed to treat rheumatoid arthritis and lupus, while inhaled preparations of these drugs may be prescribed for asthma. Topical creams containing corticosteroids may be used to heal skin conditions, and injections of these drugs are useful to reducing the pain and inflammation of tendinitis.
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.