Pain signals travel through nerves much like an electrical signal travels through a wire. If that signal can be blocked, the amount of pain you experience can be significantly reduced.
Injections can "block" the pain signals that travel to your pain via medication/numbing substances. There are various types of nerve blocks. Facet-joint blocks are used to determine whether your facet joints are causing pain. Sympathetic nerve blocks can help Dr. Gilthorpe determine whether there is existing damage to your sympathetic nerves, which run the entire span of the spine (these are responsible for controlling your body's involuntary functions).
Stellate-ganglion blocks are commonly used for nerve damage that involves the head, neck, arms and chest. These can even help a person who's battling PTSD: Studies show a stellate-ganglion block can offer patients relief from post-traumatic stress disorder for a few months up to a few years. Doctors liken this neck injection to restarting a computer, except in this case it involves the circuitry of the nervous system. Dr. Gilthorpe uses X-ray technology to guide a needle near the stellate ganglion, a bundle of nerves near the base of the neck. These nerves belong to the sympathetic nervous system, which is what prepares the body to react to stressful stimuli. He injects small increments of a pain-relieving medication to the area, thereby “blocking” the signal that’s sent to the brain. A stellate-ganglion block is an in-office procedure that takes roughly 30 minutes to an hour to complete and requires little to no downtime.
For patients with chronic pain, a "neural matrix" forms where pain signals are increased. A nerve block can break this cycle and may reduce pain even after the medication has worn off.