A nerve block relieves pain by interrupting how pain signals are sent to your brain. It is done by injecting a substance, such as alcohol or phenol, into or around a nerve or into the spine.
Nerve blocks may be used for several purposes, such as:
- To determine the source of pain.
- To treat painful conditions.
- To predict how pain will respond to long-term treatments.
- For short-term pain relief after some surgeries and other procedures.
- For anesthesia during some smaller procedures, such as finger surgery.
Nerve blocks are used to treat chronic pain when drugs or other treatments do not control pain or cause bad side effects. A test block is usually performed with local anesthetic. If you achieve good pain relief from the local anesthetic, your doctor may inject a nerve block, such as alcohol or phenol.
What To Expect After Treatment
Nerve blocks numb the nerves touched by the drugs. This relieves pain by interrupting the pain signal sent by the nerves to your brain. Depending on the type of nerve block, your pain may be numbed for a short time or a long time.
Nerve blocks for chronic pain may work for 6 to 12 months. They may have to be repeated.
Why It Is Done
Nerve blocks are used to diagnose the causes of pain. They also are used to treat chronic pain when drugs or other treatments cause bad side effects or do not control pain.
How Well It Works
Nerve blocks often relieve pain. Nerve blocks work well for some types of cancer pain, such as pain from cancer in organs such as the pancreas.footnote 1
Nerve blocks can cause serious complications, including paralysis and damage to the arteries that supply blood to the spinal cord. Other possible side effects include severely low blood pressure (hypotension), accidental injection of the alcohol or phenol into an artery, puncture of the lung, damage to the kidneys, diarrhea, and weakness in the legs.
Nerve blocks are not recommended if you have a disease that affects blood clotting, take a medicine (called a blood thinner) that prevents blood clots, have a bowel obstruction, or have any type of uncontrolled infection.
What To Think About
Doctors can deaden a nerve with a probe that generates intense heat (radiofrequency denervation or ablation) or intense cold (cryoanalgesia).
A nerve block may cause temporary muscle paralysis or a loss of all feeling in the affected area or in the surrounding area.
Current as ofDecember 19, 2018
Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine
Brian O'Brien, MD, FRCPC - Internal Medicine
Adam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Michael S. Rabin, MD - Medical Oncology
Jimmy Ruiz, MD - Medical Oncology, Hematology
Current as of: December 19, 2018