(888) 271-3826

(866) 927-7231

Nerve Blocks

What is a Nerve Block?

A nerve block is an anesthetic or anti-inflammatory injection targeted toward a certain nerve or group of nerves to treat pain. The purpose of the injection is to “turn off” a pain signal coming from a specific location in the body or to decrease inflammation in that area.

Imaging guidance is used to help the doctor place the needle in exactly the right location so that the patient can receive maximum benefit from the injection.

What are some common uses of the procedure?

People who suffer from either acute or chronic pain might have a nerve block injection to achieve temporary pain relief. Often such pain originates from the spine, but other areas commonly affected include the neck, buttocks, legs and arms. Delivering a nerve block injection allows a damaged nerve time to heal itself from a state of constant irritation. Additionally, nerve blocks can provide diagnostic information to the doctor. By performing a nerve block and then monitoring how the patient responds to the injection, the doctor can often use this information to help determine the cause or source of the pain.

How should I prepare for the procedure?

Usually, no special preparation is required prior to arrival for a nerve block procedure. You may be asked to wear a gown during the procedure.

You will probably be asked to use the restroom before the procedure.

What does the equipment look like?

The injection itself will be administered with a syringe much like one that would be used for a routine vaccination. The doctor will fill the syringe with medication. The type of medication used depends on individual patient needs.

The imaging is painless and involves the use of x-rays to obtain essential images that allow the physician to place the needle in exactly the right location for the injection.

The medication delivered by the injection will be placed as close to the site of pain as possible. It will then “shut down” the pain receptors within the nerve(s) causing the problem.

How is the procedure performed?

Nerve blocks usually take only minutes to administer.

You will be positioned on a table or other surface to allow the doctor access to the site(s) to be injected. The doctor will then identify the spot the needle needs to be placed, using palpation and/or imaging guidance. He will clean the area with antiseptic solution, and then the needle will be inserted at a specific depth to deliver the medication as close to the problematic nerve(s) as possible.

More than one injection may be required, depending on how many areas of pain you have or how large an area needs to be covered. The doctor will most likely tell you when he or she inserts the needle and when the injection is done.

When finished, you will be allowed to rest for 15 to 30minutes to let the medication take effect. The nurse will also make sure you don’t have any unexpected side effects before you leave the doctor’s office.

What will I experience during the procedure?

You will probably feel a “pinch” when the needle is inserted. As soon as the medication is delivered, though, you should feel less discomfort. Sometimes the needle has to be inserted fairly deep to reach the nerve causing your problem. This can be temporarily uncomfortable, but it is important to hold still so that the needle is inserted correctly.

If you require an injection close to a major nerve or bundle of nerves, such as the sciatic nerve, your doctor will tell you to speak up if you get a sudden jolt of pain. This means that the needle has come too close to the major nerve and will need to be retracted and re-positioned. This happens rarely, however, so it should not be a major concern.

What are the limitations of Nerve Block?

The effects of the injection are usually immediate. It only takes a short time for the medication to achieve pain relief. However, nerve blocks are only a temporary fix—they typically last for up to one or two weeks and then wear off as they are absorbed by your body. Some patients undergo several rounds of nerve blocks before they feel a more permanent sense of relief. Others may not receive any permanent pain relief from this type of injection and may require different treatment methods to manage the pain or inflammation.

What are the benefits vs. risks?


  • Temporary pain relief
  • Temporary reduction of inflammation in the region of the spine causing pain
  • May help the doctor identify amore specific cause of pain
  • Better ability to function in daily life without the restrictions previously caused by pain


  • Infection at the injection site
  • Bleeding
  • Accidental delivery of medication into the blood stream
  • Unexpected spread of medication to other nerves
  • Hitting the “wrong” nerve in an attempt to block the targeted nerve, if the nerves are close together.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby.

For Additional Information, Click to Download

Copyright ® 2009 Radiological Society of North America, Inc. (RSNA)