A stellate ganglion block (SGB) is a method of treating certain conditions resulting from chronic (longterm) over activity of the sympathetic nervous system, which is the system that prepares our body for emergencies, (the fight or flight response). The stellate ganglion block is an injection of local anesthetic into an area of the neck (cervical sympathetic trunk). The anesthetic temporarily and partially blocks part of the sympathetic nervous system. Although there is a sympathetic trunk on both sides of the neck, for treating chronic activation of the sympathetic nervous we only block the right side. We think this block works by “resetting” or “re-booting” the fight or flight response that has become dysfunctional (inappropriately activated) in some individuals exposed to highly stressful situations. The sympathetic nervous system controls automatic functions of our body such as heart rate, blood pressure, skin temperature, and pain perception. Too much activation can lead to long-term (chronic) poor sleep, increased irritability and poor concentration and memory, among other symptoms. Like a computer that gets stuck sometimes, this procedure is similar to rebooting your body’s emergency response system.