DEAR MAYO CLINIC: How do cortisone shots work to relieve pain? It appears that they only provide temporary relief and are often given multiple times. Is there a point at which frequent cortisone shots can be harmful to the body? How much is too much?
ANSWER: Injections of cortisone, or a similar corticosteroid, decrease inflammation in an injured part of the body. When body tissue is injured, a series of events occurs locally and within the bloodstream to promote healing. Inflammation can result from this healing process and, frequently, the inflammation causes pain. Injecting corticosteroids into the inflamed area helps to calm the inflammation. As the inflammation subsides, the pain does, too.
Cortisone is naturally produced in the body’s adrenal glands. It was discovered in the 1940s by Mayo Clinic researchers Edward Kendall, Ph.D., and Philip Hench, M.D., who first used it to treat joint disorders. Its powerful anti-inflammatory effect produced such dramatic results in people with rheumatoid arthritis that it was hailed as a miracle drug. In 1950, Drs. Kendall and Hench were awarded the Nobel Prize in Medicine for the discovery of cortisone.
In current medical practice, corticosteroids are used to treat a variety of inflammatory diseases, including bursitis, carpal tunnel syndrome, rheumatoid arthritis, tendinitis and gout. Corticosteroids can be given by mouth or injected into affected joints, including the ankle, elbow, hip, knee, shoulder, hand and wrist. Injections near the spine are also common.