The stellate ganglion is part of the sympathetic nervous system that is located in your neck. A stellate ganglion block is an injection of medication into these nerves that can help relieve pain in the head, neck, upper arm and chest. It can help increase circulation and blood flow to the arm.

 A stellate ganglion block is used to diagnose or treat circulation problems or nerve injuries, including reflex sympathetic dystrophy, causalgia, complex regional pain Syndrome, and phantom limb pain.

Your sympathetic nerves join outside your spine area in a system of nerves called ganglions. You may get pain relief from blocking and injecting steroids into the stellate ganglion in your neck area to treat pain in the upper part of your body.