Cortisone shots can relieve pain for several months after an injection, says MedicineNet.com. Cortisone isn't a painkiller like over the counter analgesics or narcotics. Rather, it is a powerful anti-inflammatory medication that reduces swelling, stiffness and pain by reducing the underlying inflammation in a painful area.
Cortisone shots often cause an increase in pain and swelling for up to 48 hours after the injection, states About.com. This is known as the "cortisone flare." It occurs when the cortisone crystallizes in the affected area after injection, causing irritation. Frequent icing of the area can help ease the discomfort.
Doctors often limit the number of cortisone shots they offer a patient during a calendar year due to the potential for serious complications, states Mayo Clinic. These complications include joint infection, weakening of nearby tendons, thinning of nearby bone, bone death and thinning of the skin and soft tissue near the injection site. The risk of these complications increase with each dose. For these reasons, it's common to limit the number of shots to three or four a year, according to Mayo Clinic.
Other short term side effects include facial flushing, local bleeding or bruising at the injection site and soreness at the injection site. Diabetics may also experience a temporary increase in blood glucose levels and should monitor themselves closely, states MedicineNet.com