Trigger point injections are used to treat pain in areas of the muscle called trigger points, which are knots of muscle that forms when muscle fails to relax. In some cases, a trigger point can be felt under the skin. In addition, they cause irritation to the surrounding nerves and cause referred pain, or pain that is felt in another part of the body.
Trigger point injections deliver a dose of steroid and anesthetic directly into the painful muscle. Trigger point injections can also be used to treat fibromyalgia and tension headaches. This treatment can target many types of muscle groups including those in the arms, legs, lower back and neck.