To perform a cortisone injection, the doctor uses a syringe to inject cortisone (a steroid) into a part of the body to treat inflammation, according to About.com. The exact procedures vary according to the type of ailment being treated.
Cortisone injections treat pain by reducing inflammation. The medication may be injected directly into an inflamed area such as a joint, lesion or muscle, according to HealthGrades. Alternatively, the cortisone may be injected near the spinal canal or into the blood stream. The patient is awake, and the injection can often be a briefly painful procedure. The doctor may use a local anesthetic on the skin and/or in the injection itself to decrease pain, HealthGrades notes.