Sympathetic nerve block

Sympathetic Nerve Block

Sympathetic nerve block: Overview

A sympathetic nerve block is an injection of medicine around nerves in your neck or back. This nerve block is used for problems such as chronic regional pain syndrome and pain from some types of cancer.

Sympathetic nerves spread out from your spine. They control some of the body functions you have no control over, like blood flow and digestion. They also carry pain signals. When this system isn't working right, you can have long-term (chronic) pain.

The nerves come together in groups called ganglions throughout your body. This is where the nerve block is done. Your doctor will decide which group of nerves needs this treatment.

The nerve block contains anesthetic, which usually numbs the nerves. It may also contain a steroid, which may reduce swelling and pain. Steroids take a few days, and they don't always work.

How is a sympathetic nerve block done?

First the doctor will use a tiny needle to numb the skin. Then the doctor puts the nerve block needle into the numbed area. Your doctor may use X-rays or ultrasound to help guide the needle. You may feel some pressure. But you should not feel pain.

After sympathetic nerve block: When to call

Call 911 anytime you think you may need emergency care. For example, call if:

  • You passed out (lost consciousness).
  • You have severe trouble breathing.
  • You are unable to move an arm or a leg at all.

Call your doctor now or seek immediate medical care if:

  • You have new or worse symptoms in your arms, legs, chest, belly, or buttocks. Symptoms may include:
    • Numbness or tingling.
    • Weakness.
    • Pain.
  • You lose bladder or bowel control.
  • You have signs of infection, such as:
    • Increased pain, swelling, warmth, or redness.
    • A fever.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • You are not getting better as expected.

How do you prepare for a sympathetic nerve block procedure?

Procedures can be stressful. This information will help you understand what you can expect. And it will help you safely prepare for your procedure.

Preparing for the procedure

  • Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
  • Understand exactly what procedure is planned, along with the risks, benefits, and other options.
  • Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your procedure. Your doctor will tell you if you should stop taking any of them before the procedure and how soon to do it.
  • If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your procedure. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.
  • Make sure your doctor and the hospital have a copy of your advance directive. If you don’t have one, you may want to prepare one. It lets others know your health care wishes. It’s a good thing to have before any type of surgery or procedure.

How can you care for yourself after a sympathetic nerve block?

Activity

  • You may want to do less than normal for a few days. Or you may be able to return to your daily routine.
  • You may shower if your doctor okays it.
  • Do not take a bath for the first 24 hours, or until your doctor tells you it is okay.

Diet

  • You can eat your normal diet.

Medicines

  • Your doctor will tell you if and when you can restart your medicines. You will also be given instructions about taking any new medicines.
  • If you stopped taking aspirin or some other blood thinner, your doctor will tell you when to start taking it again.
  • Be safe with medicines. Read and follow all instructions on the label.
    • If the doctor gave you a prescription medicine for pain, take it as prescribed.
    • If you are not taking a prescription pain medicine, ask your doctor if you can take an over-the-counter medicine.
  • If you normally take a blood thinner, be sure to get instructions about when to start taking it again.

Ice

  • If the site of your injection feels sore or tender, put ice or a cold pack on it for 10 to 20 minutes at a time. Put a thin cloth between the ice and your skin.

©2011-2025 Healthwise, Incorporated

The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.

Walk-in services

Find a walk-in clinic

Same-day primary care services

Learn more

Onsite diagnostic tests

Find same-day care

Hyperbaric oxygen therapy (HBOT)

Find a wound care doctor