Cortisone (/ˈkɔːrtᵻsoʊn/ or /ˈkɔːrtᵻzoʊn/; 17-hydroxy-11-dehydrocorticosterone) is a 21-carbon steroid hormone. It is one of the main hormones released by the adrenal gland in response to stress. In chemical structure, it is a corticosteroid closely related to cortisol. It is used to treat a variety of ailments and can be administered intravenously, orally, intraarticularly (into a joint), or transcutaneously. Cortisone suppresses the immune system, thus reducing inflammation and attendant pain and swelling at the site of the injury. Risks exist, in particular in the long-term use of cortisone.