Stellate Ganglion Block

Modal Pain’s approach to the stellate ganglion block

The stellate ganglion is a small collection of sympathetic nerves at the base of the front of the neck, near the C7 vertebra. The block is placed just above it, at the C6 level, where the medicine spreads down to it. The ganglion relays “fight-or-flight” signals to the head, neck, and arm. A stellate ganglion block (SGB) places local anesthetic around that bundle to switch the signaling off for a while. Dr. Alex Movshis performs every block personally, at the C6 level, using ultrasound and fluoroscopic guidance to work safely around the carotid and vertebral arteries, the thyroid, and the airway.

This page does something most clinic pages won’t: it separates the very different reasons patients get this block. One use, complex regional pain syndrome, is established and covered by insurance. Others, including the ones that bring people in after reading about them online, are off-label, where the science is genuinely early. We’ll tell you which is which.

How the block works

The sympathetic nervous system controls things you don’t think about — blood-vessel tone, sweating, the “alarm” response. When that system is stuck in overdrive in one region (a painful, swollen, color-changing arm in CRPS; a hyper-aroused nervous system in PTSD), temporarily interrupting it can break the loop. The anesthetic wears off within a day, but the reset sometimes outlasts the drug, which is the rationale behind using the block for conditions far beyond ordinary pain.

The block produces Horner’s syndrome on the treated side: a drooping eyelid, a smaller pupil, a red eye and a stuffy nostril. It is expected and temporary, and it shows the anesthetic reached the sympathetic nerves. It does not show whether the block will help, and neither does a warm hand, which often falls short of the usual temperature target after a well-placed block. Success is judged case by case, by what happens to your symptoms.

Complex regional pain syndrome: the use insurers cover

CRPS of the arm or hand is the classic indication, and the one that Aetna, UnitedHealthcare, Cigna and Anthem all list as medically necessary when their criteria are met. The criteria differ by plan. Aetna asks that the block be part of a rehabilitation program after standard medicines have failed (Aetna CPB 0863). Cigna’s guideline limits coverage to CRPS of the limbs and caps therapeutic blocks at six in 12 months (eviCore CMM-209). The guideline Anthem plans use caps blocks at six per lifetime (Carelon). UnitedHealthcare covers sympathetic blocks for CRPS and pancreatic cancer pain (UnitedHealthcare 2026T0627L). Our office checks your plan’s policy and handles prior authorization before the first block.

One honest caveat: even here, the highest-tier evidence is thinner than most patients assume. A 2023 Cochrane overview found no high-certainty evidence for any CRPS treatment (Ferraro et al., 2023). A 2024 meta-analysis of 12 randomized trials found SGB reduced pain intensity in CRPS versus controls, with few side effects, while calling for larger studies (Tian et al., 2024). We use the block both to diagnose (does turning off the sympathetic supply relieve the pain?) and to treat, alongside physical therapy.

Other medical uses that insurers generally don’t cover

The block has a long history in a few other conditions, but none of the commercial policies we reviewed covers it for them, and Aetna calls it experimental for postherpetic neuralgia (Aetna CPB 0725). When we agree the block fits, it is a $1,000 self-pay session.

• Shingles pain and postherpetic neuralgia (PHN). Used for pain control during acute shingles of the head, neck, or arm and for established PHN. For preventing PHN, the evidence favors epidural and paravertebral blocks over SGB (Kim et al., 2017).
• Raynaud’s and upper-limb circulation problems. Blocking the sympathetic supply opens up blood vessels, which can improve blood flow to the hand and serves as a test before more durable treatments. The supporting evidence is case-level (Singh & Rajarathinam, 2024).

Off-label uses (self-pay)

These are the uses people increasingly ask about. They are off-label, not an FDA-labeled indication, and not covered by insurance. Aetna names PTSD and long COVID as experimental uses of the block (Aetna CPB 0863), and the other major insurers cover it only for CRPS. They are billed as a $1,000 self-pay session. We’re willing to perform them for appropriately selected patients, and we’re equally willing to tell you what the evidence does and doesn’t show.

Long COVID

Patients sometimes come in for an off-label SGB for long-COVID symptoms — lingering fatigue, brain fog, racing heart, or a distorted sense of smell — often after their neurologist or primary doctor raises it. The theory is that long COVID involves a dysregulated, over-firing sympathetic nervous system, and that the block may help reset it.

Here’s the honest state of the evidence. There is no randomized, sham-controlled trial for long COVID as a whole. What exists is small and uncontrolled. A 20-patient open-label pilot reported meaningful improvements in autonomic symptoms, pain, sleep, and fatigue at four weeks (Wang et al., 2025). A single-practice retrospective review reported that most of 41 patients felt better afterward (Pearson et al., 2023). And there are case reports of recovered smell and energy. Against that, the one randomized, placebo-controlled trial in this area, for a distorted sense of smell after COVID, found the block no better than a saline injection: 43% improved against 38% (Farrell et al., 2025). And at least one published case describes the block simply not working, with the patient only improving after a different treatment (Butler, 2024). Without a control group, some of the reported benefit could be placebo or the natural, gradual recovery long COVID often follows. So we offer it as a reasonable thing to try for the right patient — not a proven cure — and we’d rather you go in clear-eyed.

Post-traumatic stress (PTSD)

This is the most-studied off-label use, and the trials disagree. A multisite randomized trial in service members found two right-sided blocks reduced PTSD symptoms more than a sham injection over 8 weeks (Rae Olmsted et al., 2020). An earlier randomized sham-controlled trial found no significant difference (Hanling et al., 2016), and a 2026 placebo-controlled pilot found the block added nothing measurable to cognitive processing therapy (Held et al., 2026). A 2025 meta-analysis pooled a modest benefit while emphasizing how few trials exist (Yang et al., 2025), and the 2023 VA/DoD PTSD guideline recommends neither for nor against the block. We give two treatments 2 weeks apart on the right side, at the C6 level and also at C4 when the anatomy allows, and only for patients whose PTSD is being treated by a therapist or psychiatrist. The fair summary: an off-label adjunct that helps some people, most studied in military populations, used alongside trauma-focused therapy rather than instead of it. The trials, the risks and who should not have it are in our guide to stellate ganglion block for PTSD.

Menopausal hot flashes

Of the three off-label uses, this one has the strongest dedicated trial. A randomized, sham-controlled study found SGB significantly reduced moderate-to-severe hot flashes and objectively measured flashes, even though it didn’t change total flash count (Walega et al., 2014); the original pilot work in breast-cancer survivors who couldn’t take hormones was striking (Lipov et al., 2008). It’s a reasonable non-hormonal option to discuss for severe symptoms — still off-label, still a small evidence base.

Safety

A stellate ganglion block is generally safe in trained hands with image guidance. In a 1992 survey of about 45,000 blocks, from before image guidance was common, severe complications occurred in 1.7 per 1,000 (Wulf and Maier, 1992). The expected effects, a drooping eyelid, a hoarse voice or a lump-in-the-throat feeling, wear off as the numbing medicine does, within 24 hours. The rare serious risks, which ultrasound and fluoroscopy are used to prevent, include injection into a blood vessel, which can cause a seizure, and bleeding in the neck, which can show up hours or even days later (Goel et al., 2019). We observe you for 30 to 60 minutes after the block. Someone must take you home, or take a car service such as Uber or a taxi, not the subway and not your own car. How often each side effect happens, how long it lasts, and the warning signs to know are on the stellate ganglion block aftercare page. Because a single block’s benefit is often short-lived, repeat blocks are common, and each carries the same risks, which is why we reassess rather than repeat a block that did not help.

If a stellate ganglion block is something you or your referring physician are considering — for a covered pain condition or an off-label reason — book a consultation or call (646) 290-6660, and we’ll give you a straight read on whether it makes sense for you.

References

• Ferraro MC, Cashin AG, Wand BM, et al. Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews. Cochrane Database Syst Rev. 2023;6(6):CD009416. doi:10.1002/14651858.CD009416.pub3 · PubMed
• Tian Y, Hu Y, Hu T, et al. Stellate Ganglion Block Therapy for Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis. Pain Physician. 2024;27(4):175–184. PubMed
• Harden RN, McCabe CS, Goebel A, et al. Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition. Pain Med. 2022;23(Suppl 1):S1–S53. doi:10.1093/pm/pnac046 · PubMed
• Kim HJ, Ahn HS, Lee JY, et al. Effects of applying nerve blocks to prevent postherpetic neuralgia in patients with acute herpes zoster: a systematic review and meta-analysis. Korean J Pain. 2017;30(1):3–17. doi:10.3344/kjp.2017.30.1.3 · PubMed
• Johnson RW, Rice AS. Clinical practice. Postherpetic neuralgia. N Engl J Med. 2014;371(16):1526–33. doi:10.1056/NEJMcp1403062 · PubMed
• Singh H, Rajarathinam M. Stellate ganglion block beyond chronic pain: A literature review on its application in painful and non-painful conditions. J Anaesthesiol Clin Pharmacol. 2024;40(2):185–191. doi:10.4103/joacp.joacp_304_22 · PubMed
• Lipov EG, Joshi JR, Sanders S, et al. Effects of stellate-ganglion block on hot flushes and night awakenings in survivors of breast cancer: a pilot study. Lancet Oncol. 2008;9(6):523–32. doi:10.1016/S1470-2045(08)70131-1 · PubMed
• Walega DR, Rubin LH, Banuvar S, Shulman LP, Maki PM. Effects of stellate ganglion block on vasomotor symptoms: findings from a randomized controlled clinical trial in postmenopausal women. Menopause. 2014;21(8):807–14. doi:10.1097/GME.0000000000000194 · PubMed
• Rae Olmsted KL, Bartoszek M, Mulvaney S, et al. Effect of Stellate Ganglion Block Treatment on Posttraumatic Stress Disorder Symptoms: A Randomized Clinical Trial. JAMA Psychiatry. 2020;77(2):130–138. doi:10.1001/jamapsychiatry.2019.3474 · PubMed
• Hanling SR, Hickey A, Lesnik I, et al. Stellate Ganglion Block for the Treatment of Posttraumatic Stress Disorder: A Randomized, Double-Blind, Controlled Trial. Reg Anesth Pain Med. 2016;41(4):494–500. doi:10.1097/AAP.0000000000000402 · PubMed
• Held P, Pridgen SA, Smith DL, et al. Enhancing cognitive processing therapy via stellate ganglion blocks: a pilot randomized trial. J Trauma Stress. 2026. doi:10.1002/jts.70116 · PubMed
• Yang Y, Pu R, Zhang D, et al. Stellate ganglion blockade for the treatment of post-traumatic stress disorder: A systematic review and meta-analysis. Auton Neurosci. 2025;262:103360. doi:10.1016/j.autneu.2025.103360 · PubMed
• Wang S, Salway RJ, Nicklay M, Kuo J. Effectiveness of Dual Sympathetic Blocks for Sympathetically Mediated Symptoms in Post-acute Sequelae of SARS-CoV-2 (PASC): An Open-Label, Non-randomized Pilot Study. Cureus. 2025;17(3):e81530. doi:10.7759/cureus.81530 · PubMed
• Pearson L, Maina A, Compratt T, et al. Stellate Ganglion Block Relieves Long COVID-19 Symptoms in 86% of Patients: A Retrospective Cohort Study. Cureus. 2023;15(9):e45161. doi:10.7759/cureus.45161 · PubMed
• Butler CS. Use of Neuromodulation to Treat Post-COVID Neuropathic Pain: A Case Report. Pain Med Case Rep. 2024;8(7):253–256. PubMed
• Farrell NF, Crock LW, Islam A, et al. Stellate ganglion block for the treatment of COVID-19-induced parosmia: a randomized clinical trial. JAMA Otolaryngol Head Neck Surg. 2025;151(8):741–749. doi:10.1001/jamaoto.2025.1304 · PubMed
• Wulf H, Maier C. Complications and side effects of stellate ganglion blockade. Results of a questionnaire survey. Anaesthesist. 1992;41(3):146–51. PubMed
• Goel V, Patwardhan AM, Ibrahim M, et al. Complications associated with stellate ganglion nerve block: a systematic review. Reg Anesth Pain Med. 2019. doi:10.1136/rapm-2018-100127 · PubMed
• Aetna. Clinical Policy Bulletin 0863: Nerve Blocks. Last review 07/23/2026. aetna.com
• Aetna. Clinical Policy Bulletin 0725: Post-Herpetic Neuralgia. Last review 10/20/2025. aetna.com
• UnitedHealthcare. Commercial Medical Policy 2026T0627L: Sympathetic Blockade. Effective 09/10/2026. uhcprovider.com
• eviCore healthcare for Cigna. CMM-209: Regional Sympathetic Blocks, version 1.0.2024. evicore.com
• Carelon Medical Benefits Management. Interventional Pain Management guideline, Regional Sympathetic Nerve Block. Effective 06/14/2026. carelonmedicalbenefitsmanagement.com