A stellate ganglion block is an injection of local anesthetic in the sympathetic nerve tissue of the neck. These nerves are a part of the sympathetic nervous system.
The nerves are located on either side of the voice box, in the neck. A stellate ganglion block blocks the sympathetic nerves that go to the arms, and, to some degree, the sympathetic nerves that go to the face. This may in turn reduce pain, swelling, color and sweating changes in the upper extremity and may improve mobility.
It is done as a part of the treatment of Reflex Sympathetic Dystrophy (RSD), Sympathetic Maintained Pain, Complex Regional Pain Syndrome and Herpes Zoster (shingles) involving an arm or the head and face.