What is a sympathetic nerve block?

A sympathetic nerve block for pain is believed by many pain health care providers to be an effective method for controlling chronic pain. However, there is not a great deal of medical evidence to show whether these blocks are helpful. This therapy targets the sympathetic nervous system, a series of nerves that spread out from your spine to your body to help control several involuntary body functions, or body functions that you have no control over. These include blood flow, digestion, and sweating.

Why are sympathetic nerve blocks used?

A sympathetic nerve block can be used to diagnose or treat pain involving the nerves of the sympathetic nervous system. Examples of conditions for which a sympathetic nerve block might be used include:

  • Pain from spasms in the blood vessels
  • Complex regional pain syndrome, previously called reflex sympathetic dystrophy and causalgia
  • Raynaud’s syndrome
  • Some types of chronic stomach pain
  • Excessive sweating