Sympathetic Nerve Block

A sympathetic nerve block helps your healthcare provider find the cause of the burning feeling, pain, or tingling in your arms and hands or legs and feet. During the test, medicine is injected near your spine. This “blocks” the sympathetic nerves in that region. If these nerves are causing your problem, the injection will ease your symptoms for 1 hour up to a few days. Or it may provide more long-lasting symptom relief. It's used to both diagnose and treat nerve disorders.

What are the sympathetic nerves?

The sympathetic nervous system is a network of nerves all over your body. The nerves branch from your spine. They control some body functions. These include closing blood vessels and opening the sweat glands. A problem with these nerves can affect blood flow. Symptoms are often felt in the hands or feet. They may hurt, burn, feel cold, or be sore to the touch.

Sympathetic ganglions

The sympathetic nervous system is controlled by bunches of nerves called ganglions. One large ganglion, called the stellate ganglion, helps control nerves in the upper body. In the lower body, nerves are controlled by several ganglions that make up the sympathetic chain.

Male figure from behind showing nerves in back and arms.

Risks and complications

Risks and complications are rare, but can include:

  • Bleeding or fluid leaking in the spinal cord

  • A hole (puncture) in a blood vessel

  • Infection

  • Lung puncture (collapsed lung)

  • Nerve injury

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