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.
treat painful conditions.
- To predict how pain will respond to
- 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
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.
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.
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.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, are taking blood-thinning drugs (such as heparin or warfarin),
have a bowel obstruction, or have any type of uncontrolled infection.
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.
Complete the special treatment information form (PDF) (What is a PDF document?) to help you understand this treatment.
National Comprehensive Cancer Network (2013). Adult cancer pain. NCCN Clinical Practice Guidelines in Oncology, version 1.2013. Available online: http://www.nccn.org/professionals/physician_gls/pdf/pain.pdf.