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

The injections usually contain a corticosteroid medication and a local anesthetic. Often, you can receive one at your doctor's office. Because of potential side effects, the number of shots you can get in a year generally is limited.

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

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

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

• Cartilage damage
• Death of nearby bone
• Joint infection
• Nerve damage
• Temporary facial flushing
• Temporary flare of pain and inflammation in the joint
• Temporary 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.

In general, you shouldn't get cortisone injections more often than every six weeks and usually not more than three or four times a year.

If you take blood thinners, you might need to stop taking them for several days before your cortisone shot to reduce bleeding or bruising risk. Some dietary supplements also have a blood-thinning effect. Ask your doctor what medications and supplements you should avoid before your cortisone shot.

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

During the cortisone shot

Your doctor might ask you to change into a gown. You'll then be positioned so that your doctor can easily insert the needle.

The area around the injection site is cleaned. Your doctor might also apply an anesthetic spray to numb the area where the needle will be inserted. In some cases, your doctor might use ultrasound or a type of X-ray called fluoroscopy to watch the needle's progress inside your body — so as to place it in the right spot.

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

The medication is then released into the injection site. Typically, cortisone shots include a corticosteroid medication to relieve pain and inflammation over time and an anesthetic to provide immediate pain relief.

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 your cortisone shot, your doctor might ask that you:

• Protect the injection 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.
• Apply ice to 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 that last more than 48 hours.

Results of cortisone shots typically depend on the reason for the treatment. Cortisone shots commonly cause a temporary flare in pain and inflammation for up to 48 hours after the injection. After that, your pain and inflammation of the affected joint should decrease, and can last up to several months.