How it works
How nerve blocks work
A nerve block places medicine as close as possible to the nerve or nerves that carry your pain signals. The numbing medicine (a local anesthetic) blocks those signals for a while. A steroid, which is an anti-inflammatory medicine, is sometimes added to calm irritation around the nerve.
Nerve blocks have two main uses:
- To find the source of pain. If your pain eases a lot after a block, that is a sign the nerve that was blocked carries your pain. This helps your provider plan the next step.
- To ease pain. A block may give a period of relief so you can stay active and take part in the rest of your care plan.
At Lewis Pain & Physical Medicine, nerve blocks are performed by a physician using x-ray images (fluoroscopy) to guide the needle.
Who may benefit
Who may be a candidate for a nerve block
A nerve block may be considered for pain from:
- The facet joints of the neck or back
- Nerves at the back of the head, such as occipital neuralgia and some headaches
- Complex regional pain syndrome (CRPS)
- Peripheral neuropathy or a nerve injury in one area
- Some long-lasting pain after surgery or an injury, decided case by case
You may be a candidate if your pain seems to come from a specific nerve or area and other care has not given you enough relief. Your provider will look at your history, your symptoms and any imaging, then talk with you about whether a nerve block makes sense.
Having one of these conditions does not by itself mean a nerve block is right for you.
Types of nerve blocks
Types of nerve blocks
The type of block depends on where your pain is and which nerves may be carrying it.
- Medial branch blocks Numbing medicine near the small nerves of the spine’s facet joints, mainly used to find out whether a facet joint is a source of neck or back pain.
- Epidural steroid injections A numbing medicine and a steroid placed near irritated spinal nerves.
- Occipital nerve blocks Numbing medicine near the nerves at the back of the head.
- Peripheral nerve blocks Numbing medicine near a single nerve outside the spine, for pain in one area.
- Genicular nerve blocks Numbing medicine near the nerves that carry pain from the knee.
- Intercostal nerve blocks Numbing medicine near a nerve that runs between the ribs, for some chest wall or rib pain.
- Celiac plexus blocks Numbing medicine near a group of nerves in the upper abdomen, for some long-lasting abdominal pain, including some cancer-related pain.
- Sympathetic nerve blocks Numbing medicine near a cluster of sympathetic nerves, described below.
Sympathetic nerve blocks
Sympathetic nerve blocks
The sympathetic nerves are part of the nervous system that works automatically, controlling things such as blood flow and sweating. In some pain conditions, such as complex regional pain syndrome (CRPS), these nerves appear to play a part in the pain.
A sympathetic nerve block places numbing medicine near a cluster of these nerves:
- Stellate ganglion block, at the front of the neck, for some pain in the arm, hand or face.
- Lumbar sympathetic block, in the lower back, for some pain in the leg or foot.
If your pain eases after the block, the sympathetic nerves are likely part of your pain, and your provider may suggest more blocks as part of your plan.
After a stellate ganglion block, it is common to have a droopy eyelid, a hoarse voice or a warm feeling in the arm on that side. After a lumbar sympathetic block, the leg may feel warm. These effects usually wear off as the numbing medicine does.
What to expect
What to expect before, during and after a nerve block
Before your block
You will meet with your provider to review your history and symptoms. Tell the team about your medicines, especially blood thinners, and about any allergies. Your provider will discuss sedation options for your procedure at your visit, and your team will tell you how to prepare. If sedation is used, you will need someone to drive you home.
During the procedure
You lie on a table in the position that gives the best access to the nerve. The skin is cleaned and numbed. Using x-ray images, a thin needle is guided near the nerve, and a small amount of contrast dye may be used to check its position. The medicine is then injected and the needle is removed. You may feel pressure or a brief sting.
After your block
You will be watched for a while before you go home. The area may feel numb, weak or warm while the numbing medicine works, and you may have soreness where the needle went in. You may be asked to record your pain levels afterward so you and your provider can judge how the block worked. Our office will follow up with you.
Do not stop or change any medicine, including a blood thinner, unless the clinician who prescribes it tells you to.
Benefits and limitations
Possible benefits and limitations
The numbing medicine works quickly, and its effect usually lasts hours, though this varies. If a steroid is used, any relief from it may take a few days to begin. How long relief lasts varies from person to person, and some people do not get the relief they hoped for.
A block that helps can point to the next step, such as radiofrequency ablation for some nerves, and some blocks are given as a series. Your provider can give you a realistic idea of what to expect for your condition.
Risks and side effects
Risks and side effects of nerve blocks
Like any injection, a nerve block has risks. They can include soreness, bleeding or infection where the needle went in, an allergic reaction, medicine reaching a blood vessel or nearby nerves, temporary numbness or weakness, or a temporary rise in pain. Steroids can also have effects on blood sugar and on other parts of the body.
Please talk with your provider about the risks that apply to you before deciding.
Common questions
Questions about nerve blocks
Your provider can talk through your own plan at your visit.
What is a nerve block injection?
A nerve block is an injection of numbing medicine, sometimes with a steroid, near a specific nerve or group of nerves. It may be used to find out which nerve is carrying your pain, to ease pain for a period of time, or both. At our Frisco office, the needle is guided with x-ray images (fluoroscopy).
What is a sympathetic nerve block?
A sympathetic nerve block places numbing medicine near a cluster of sympathetic nerves, such as the stellate ganglion in the neck or the lumbar sympathetic nerves in the lower back. It may be considered for pain conditions in which these nerves seem to play a part, such as complex regional pain syndrome (CRPS). If the block helps, your provider may suggest more blocks as part of your plan.
Is a nerve block painful?
The skin is numbed first. You may feel a pinch or brief sting when the needle goes in, and some pressure during the injection. Your provider will discuss sedation options for your procedure at your visit.
How long does a nerve block last?
It varies from person to person and by type of block. The numbing medicine usually wears off within hours, and relief from a steroid, if one is used, may last longer for some people. How long relief lasts also helps your provider decide on the next step.
What is recovery like, and when can I drive or go back to work?
If sedation is used, you will need someone to drive you home. The area may feel numb or weak for a while, so take care with that arm or leg. Your team will tell you when you can drive and return to work and your usual activities.
Will I need more than one nerve block?
Sometimes. Some blocks are given as a series, and a block that helps may lead to a different treatment, such as radiofrequency ablation. It depends on what your provider finds and how you respond.
Related care
Clinical references
Individual results are not guaranteed and may vary from person to person. This page shares general information. It is not medical advice and does not replace a visit with a qualified clinician.