Trigger point injection (TPI): may be an option for treating pain in some patients. TPI is a procedure used to treat painful areas of muscle that contain trigger points, or knots of muscle that form when muscles do not relax. Many times, such knots can be felt under the skin. Trigger points may irritate the nerves around them and cause referred pain, or pain that is felt in another part of the body.
Trigger point injections can be used to treat a number of conditions including fibromyalgia, tension headache, and myofascial pain syndrome. A trigger point injection involves the injection of medication directly into the trigger point.
