Cortisone shots are injections that can help relieve pain, swelling and irritation in a specific area of your body. They're most often injected into joints — such as the ankle, elbow, hip, knee, shoulder, spine or wrist. Even the small joints in the hands or feet might benefit from cortisone shots.

A cortisone shot usually contains a corticosteroid medicine for pain relief over time and a local anesthetic for pain relief right away. Often, you can receive one at your doctor's office. Because of potential side effects, the number of shots given in a year generally is limited.

Cortisone shots might be most effective in treating inflammatory arthritis, such as rheumatoid arthritis. They also can be part of treatment for other conditions, including:

• Back pain.
• Bursitis.
• Gout.
• Osteoarthritis.
• Psoriatic arthritis.
• Rheumatoid arthritis.
• Tendinitis.

Potential side effects of cortisone shots increase with larger doses and more frequent use. Side effects can include:

• Cartilage damage.
• Death of nearby bone.
• Joint infection.
• Nerve damage.
• Short-term facial flushing.
• Short-term flare of pain, swelling and irritation in the joint.
• Short-term increase in blood sugar.
• Tendon weakening or rupture.
• Thinning of nearby bone (osteoporosis).
• Thinning of skin and soft tissue around the injection site.
• Whitening or lightening of the skin around the injection site.

Limits on the number of cortisone shots

There's concern that repeated cortisone shots might damage the cartilage within a joint. So doctors typically limit the number of cortisone shots into a joint. The number can depend on the joint, the diagnosis and other factors.

If you take blood thinners, you might need to stop taking them for a few days before the cortisone shot. This reduces the risk of bleeding or bruising. Some dietary supplements also have a blood-thinning effect. Ask your care provider what medicines and supplements to avoid before a cortisone shot.

Tell your care provider if you've had a temperature of 100.4 F (38 C) or greater in the previous two weeks.

During the cortisone shot

Your care provider might ask you to change into a gown. You'll then be positioned so that the needle can be inserted easily into the joint.

The area around the injection site is cleaned. The care provider might also spray a medicine that numbs an area where the needle will be inserted. In some cases, the care provider uses an ultrasound or a type of X-ray called fluoroscopy to see the needle's progress inside the body — so as to place it in the right spot.

You'll likely feel some pressure when the needle is inserted. Let your care provider know if you have a lot of discomfort.

The medicine is then released into the injection site. Typically, cortisone shots include a corticosteroid medicine to relieve pain, swelling and irritation over time plus an anesthetic medicine to provide pain relief right away.

After the cortisone shot

Some people have redness and a feeling of warmth of the chest and face after a cortisone shot. If you have diabetes, a cortisone shot might temporarily increase your blood sugar levels.

After a cortisone shot, your care team might ask that you:

• Protect the area for a day or two. For instance, if you received a cortisone shot in your shoulder, avoid heavy lifting. If you received a cortisone shot in your knee, stay off your feet when you can.
• Use ice on the injection site as needed to relieve pain. Don't use heating pads.
• Not use a bathtub, hot tub or whirlpool for two days. It's OK to shower.
• Watch for signs of infection, including increasing pain, redness and swelling lasting more than 48 hours.

Results of cortisone shots typically depend on the reason for the treatment. Cortisone shots commonly cause a short-term flare in pain, swelling and irritation for up to two days after the injection. After that, the pain, swelling and irritation should generally lessen. The pain relief can last up to several months.