According to Mayo Clinic, joint infection, nerve damage, tendon weakening or rupture and temporary pain or inflammation can all be negative side effects of a cortisone shot. About.com adds that the most common side effect is called cortisone flare. This is when the cortisone that is injected crystallizes, causing more discomfort than prior to the injection; it does go away with time and an ice regimen.
About.com says that the skin around the injection sight may whiten, but this is not harmful. In rare instances, infections or deadening of the bone can be quite serious and must be addressed by medical professionals quickly. The Mayo Clinic explains that cortisone injections should be limited and administered no less than six weeks apart due to the fact that the cartilage deteriorates with each injection.
About.com defines cortisone as an anti-inflammatory medication that is injected into a joint or muscle that causes consistent pain. Cortisone is found in the body naturally and is produced by the adrenal gland. Cortisone injections are created synthetically and are designed to mimic natural cortisone. These injections are commonly used for tennis elbow, carpal tunnel syndrome, arthritis and a number of other problems that may cause increased inflammation in the joint, according the About.com.