Stellate Ganglion Block

Medically reviewed by Joshua L. Hare, DO, Founder & Medical Director

Conditions Treated

Complex regional pain syndrome (CRPS) of the upper extremity, sympathetically maintained pain, vascular insufficiency of the arm, phantom limb pain, post-herpetic neuralgia of the face or arm

Stellate Ganglion Block at a Glance

What it is	A local-anesthetic block of the sympathetic nerve chain in the neck, at the C6–C7 level[1]
Time in the procedure room	About 15–20 minutes
Guidance	Ultrasound or fluoroscopy — the literature strongly recommends image guidance[1] for this block
Expected right after	A droopy eyelid, small pupil and warm face on the treated side — temporary, and a sign the block reached its target
Going home	Same day; a driver is required
Relief per block	Hours to weeks; a series may build cumulative benefit

How It Works

Under fluoroscopic or ultrasound guidance, the physician places a needle near the stellate ganglion at the C6-C7 level.[1] Local anesthetic is injected to temporarily block the sympathetic nerve chain. Successful block is confirmed by development of Horner syndrome (drooping eyelid, constricted pupil, facial warmth on the treated side).

The sympathetic chain is the body’s “fight or flight” wiring, and in some pain conditions it becomes part of the problem. The pain relieved by this block is called sympathetically mediated pain:[1] abnormal cross-talk between the sympathetic and sensory nervous systems, so signals that should regulate blood flow end up feeding pain instead. Blocking the ganglion interrupts that cross-talk; the clinical reference describes its effects as blocked neural connections, improved blood supply to the region, and reduced stress-hormone levels.[1]

A Treatment That Is Also a Test

This block does double duty. Beyond relief, it is a diagnostic tool that confirms whether sympathetically mediated pain is present[1] at all. If the block clearly helps, that tells your provider the sympathetic system is involved — and it opens a treatment path. If it does not, that is genuinely useful too: it steers the workup toward other pain generators instead of repeating a block that will not help.

Who It Helps — and Who Needs a Different Plan

The best-known use is complex regional pain syndrome of the arm, head or neck;[1] the literature also describes it for post-herpetic neuralgia, chronic post-surgical pain, phantom limb pain and circulation problems of the arm, among others. Some conditions rule it out or change the risk calculation: a recent heart attack, certain heart-rhythm problems, glaucoma, severe emphysema, and anticoagulation.[1] Your provider reviews all of this with you before any block goes on the schedule.

The Day of the Procedure

1. Positioning and monitoring. You lie face up with your neck gently extended; vital signs are monitored throughout.
2. Imaging first. The target sits near important vessels and nerves, which is why the literature strongly recommends image guidance[1] — the needle path is planned and watched on ultrasound or fluoroscopy, never by feel alone.
3. The block. After skin numbing, a small volume of local anesthetic is delivered at the ganglion. The procedure itself takes about 15–20 minutes.
4. Observation, then home. A short recovery-room stay, then discharge the same day. A driver is required.

What You Will Notice Right After

On the treated side	A drooping eyelid, smaller pupil and warm, flushed skin — Horner syndrome. It looks alarming and is expected: it means the anesthetic reached the sympathetic chain. It resolves within hours as the anesthetic wears off.
Your voice	Temporary hoarseness can occur and passes with the anesthetic.
The pain	If the sympathetic system is driving your pain, relief can be apparent quickly. How long it lasts varies — hours to weeks per block — and a series may build cumulative benefit.

Risks

The effects above are expected and short-lived. True complications are uncommon with image guidance but are described in the literature: bleeding from nearby vessels, nerve irritation, pneumothorax, and infection.[1] The block sits close to structures that matter, which is why it is performed by trained pain clinicians, with imaging, and why your medications — blood thinners especially — are reviewed beforehand.

Common Questions

Why did my eyelid droop after the block?

Because the block worked mechanically: the sympathetic fibers that keep the eyelid raised and the pupil wide sit in the chain being blocked, so a droopy lid and small pupil on that side mean the anesthetic reached its target. It wears off within hours.

How many blocks will I need?

It depends on how you respond. Relief from one block lasts hours to weeks, and a series may build cumulative benefit — your provider maps the plan to your response, not to a fixed count.

The blocks help, but the relief keeps wearing off. What then?

Real but temporary relief is itself a useful finding, and it is what makes radiofrequency ablation or spinal cord stimulation worth considering for sustained relief.

Is it safe if I have a heart condition?

That depends on the condition — a recent heart attack and certain rhythm problems are contraindications in the clinical literature, and the evaluation screens for them. Bring your full cardiac history and medication list.

References

Clinical sources for this page.

1. Stellate Ganglion Blocks. StatPearls [Internet], National Library of Medicine; updated August 13, 2023. Back to first citation ↑