What is Stellate Ganglion Block (SGB)?
A stellate ganglion block (SGB) is a medical procedure involving the injection of a local anesthetic near the stellate ganglion, a cluster of sympathetic nerves located in the front of the neck. This block interrupts pain signals and modulates the sympathetic nervous system, which regulates blood flow, heart rate, and sweating
SGB helps many patients get relief from some or all of the following:
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Frequently asked questions (FAQ)

A stellate ganglion block (SGB) is a medical procedure in which a local anesthetic is injected around the stellate ganglion, a collection of nerves located in the neck. This nerve cluster is part of the sympathetic nervous system and helps regulate involuntary bodily functions, such as blood flow and pain responses in the head, neck, chest, and arms.
The stellate ganglion block (SGB) procedure is a minimally invasive outpatient procedure typically performed by a pain management specialist, anesthesiologist, or interventional radiologist.
You will lie on your back with your head slightly extended and turned away from the injection site (usually the right side is preferred for PTSD, though the left side may be used as well).
Your vital signs (heart rate, blood pressure, oxygen levels) will be monitored throughout the procedure.
The common side effects of a stellate ganglion block (SGB) are usually temporary and indicate that the procedure is working as expected. Most side effects result from the spread of the anesthetic to nearby nerves and structures.
No, it is recommended not to drive on the day of the procedure due to potential side effects. Arrange for someone to drive you home and stay with you for the rest of the day if needed.
The full effects of a stellate ganglion block (SGB) can vary depending on the condition being treated, but here’s a general timeline:
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Immediate effects (within minutes to 30 minutes):
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Warmth or redness in the face or arm
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Horner’s syndrome (drooping eyelid, small pupil, lack of facial sweating)
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Temporary hoarseness or nasal stuffiness
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Initial pain relief or anxiety reduction (especially in PTSD)
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Peak and Full Effects
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For pain conditions (e.g., CRPS, facial pain, migraines):
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Relief often begins within minutes to hours
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Peak effect usually occurs within 1–2 days
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Duration can range from days to months, depending on individual response
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For PTSD:
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Some patients report immediate calming or a “quieting of the mind” within 30–60 minutes
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Others notice changes over 24–72 hours
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Effects can last weeks to months; sometimes a second block on the opposite side is done within a few days to extend benefits
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The stellate ganglion block (SGB) is generally considered safe when performed by an experienced clinician, especially under ultrasound guidance. However, like any medical procedure, it carries some risks — ranging from common, mild side effects to rare but serious complications.
Common (and usually temporary) side effects
These effects are often expected and usually resolve within a few hours:
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Horner’s syndrome: drooping eyelid, small pupil, facial warmth/lack of sweating (indicates successful block)
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Hoarseness: from temporary spread to the recurrent laryngeal nerve
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Difficulty swallowing (dysphagia)
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Nasal congestion
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Warmth/redness in the arm or face
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Temporary arm numbness or weakness
Yes. However, avoid strenuous activities on the day of the procedure and follow any specific post-procedure instructions from your CIT Clinics provider.
Yes, you should avoid food for a certain period before the procedure (typically 6 hours) and clear fluids up to 2 hours before. Specific instructions will be provided during your onboarding process and treatment preparation.
The number of stellate ganglion block (SGB) treatments needed for effectiveness depends on the condition being treated, your individual response, and your treatment goals.
For PTSD and Anxiety Disorders:
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Initial treatment:
Typically starts with 1 or 2 injections — often done on both sides, a few days apart (usually right side first, then left). -
Effect duration:
Some people experience weeks to months of relief after just one or two blocks. -
Follow-up treatments:
May be repeated as needed if symptoms return — some individuals get another block every 3–6 months, though many go much longer between treatments.