Cortisone shots are injections of corticosteroids that doctors prescribe in order to reduce swelling and pain. Sometimes they're injected right into the painful joint when you're dealing with osteoarthritis, although you normally can't get more than three or four shots in the same joint per year. Too many injections in too short of a time span can cause permanent damage to cartilage. Cortisone can be taken in pill form too, but it's accompanied by long-term side effects that make it less effective. Generally, doctors turn to cortisone injections as a last resort if other osteoarthritis treatments don't work.
Corticosteroids work by affecting your immune system. When you get an injury, your body normally reacts by inflaming the area. Blood vessels swell up and your body releases irritants. Then white blood cells move toward the injury to fight infection, but they add to the swelling and irritation. Corticosteroids alter how the white blood cells work to slow down their movement toward the injury and prevent further inflammation.
Of course, as with most drug treatments, there are some possible side effects associated with cortisone injections, especially considering their influence on the immune system. Some of the less dangerous side effects include acne, Cushing's syndrome, bloating, increased chance of infection, high blood pressure, glaucoma, mood swings, weak muscles, slow healing and weight gain. Plus, if you use cortisone as a long-term treatment, you put yourself at risk for brittle or fractured bones and destroyed joint cartilage. To reduce the chance of side effects, you should avoid exercise after you get a cortisone injection. Along with the side effects you should be aware of when taking cortisone shots alone, there are certain drugs that shouldn't be used at the same time as cortisone. Your doctor needs to know about all the other drugs you're taking before you get a cortisone shot.