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Piriformis Syndrome: Symptoms, Diagnosis and Treatment

A physiotherapist stretching the hip of a person lying on a treatment couch, with the title Piriformis syndrome

By Mr Ahmed-Ramadan Sadek, Neurosurgeon · 10 min read

🎧 Listen to this guideAbout 7 minutes. Narrated in Mr Sadek’s voice using AI voice technology, from a script he has reviewed.

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Key points

  • Piriformis syndrome is pain in the buttock, often spreading down the back of the thigh, thought to come from the sciatic nerve being irritated where it passes the piriformis muscle deep in the buttock.
  • It can feel like sciatica from a slipped disc. Clues that point to the buttock are pain mainly in the buttock, pain that is worse when sitting, deep tenderness in the buttock and little or no back pain.
  • There is no single test for it. Doctors usually look for a cause in the spine first, and some use a guided injection to confirm where the pain comes from.
  • Exercise and physiotherapy come first. Guided injections may help if they do not. Surgery is kept for the few people who still have bad pain after other treatment.
  • The research is weak. Most studies are small, and experts still disagree about how to define the condition and how common it is.

Go to A&E or call 999 if you have buttock, leg or back pain together with:

  • Sciatica on both sides.
  • Weakness or numbness in both legs that is severe or getting worse.
  • Numbness around or under your genitals, or around your bottom (anus).
  • Difficulty starting to pee, being unable to pee, or not being able to control when you pee, when this is not normal for you.
  • Not noticing when you need to poo, or not being able to control it, when this is not normal for you.

These can be signs of cauda equina syndrome, which needs treatment in hospital as soon as possible. Do not drive yourself: ask someone to take you, or call 999 for an ambulance.[1]

What is piriformis syndrome?

The piriformis is a small, flat muscle deep in the buttock. It runs from the base of the spine (the sacrum) to the top of the thigh bone and helps turn the hip outwards. The sciatic nerve, the large nerve that runs down the back of the leg, leaves the pelvis just below it.[12] Piriformis syndrome is the name for buttock and leg pain that is thought to come from the nerve being squeezed or irritated as it passes this muscle.[6]

In most people the nerve passes below the muscle in one bundle. In about 10 to 15 in 100, part or all of the nerve runs through or above the muscle instead. Two large pooled analyses of anatomy studies put the usual pattern at 85 in 100[4] and 90 in 100.[5] These variations were once thought to cause the condition, but one review found they are no more common in people with piriformis syndrome than in people without it.[6]

Specialists now often use the wider term deep gluteal syndrome. This covers the sciatic nerve being caught in the buttock by the piriformis or by other structures, such as bands of tissue, other small muscles, blood vessels or the hamstring attachment.[12][14] Our buttock and leg pain guide compares it with sciatica from the spine and with a related condition called ischiofemoral impingement.

A debated diagnosis

Piriformis syndrome has been described for many decades, yet doctors still debate how to define it and how often it is the true cause of pain.[9][7] Estimates of how common it is depend heavily on how it is defined:

  • About 5 to 6 in 100 people with low back, buttock or leg pain, according to some estimates quoted in a 2024 review.[6]
  • About 17 in 100 people attending one pain clinic for long-term back pain, using an examination test and a response to injection.[10]
  • Much higher figures from questionnaire surveys. One survey of 190 university students found 61 in 100 had symptoms that fitted its definition, which shows how much the answer depends on the method used.[11]

A systematic review found that studies of how common the condition is are few, and the larger ones are at high risk of bias.[8] So the honest answer is that nobody knows exactly.

Symptoms

Two systematic reviews of published cases found four features came up most often:[9][8]

  • Pain in the buttock.
  • Pain that is worse when sitting.
  • Tenderness deep in the buttock, near the notch in the pelvis where the sciatic nerve leaves.
  • Pain brought on by movements that stretch or tighten the piriformis muscle.

The pain may spread down the back of the thigh. Back pain is usually mild or absent, and the pain is felt mainly in the buttock and hip.[3] A review of deep gluteal syndrome found that difficulty sitting for 30 minutes was a common complaint.[15]

How it differs from sciatica caused by a disc

In sciatica from the spine, a nerve root is pressed or irritated as it leaves the lower back. A slipped disc is the most common cause.[1] In piriformis syndrome, the problem is thought to lie further along the same nerve, in the buttock. NICE’s summary for GPs lists piriformis syndrome as one of the conditions that can be mistaken for sciatica.[3]

Sciatica from a discPiriformis syndrome
Where the pain isLeg pain worse than back pain, often below the knee to the foot or toesMainly the buttock and hip, may spread down the back of the thigh
Back painOften present, but less than the leg painLittle or none
What makes it worseBending, twisting, coughing or sneezingSitting
Numbness or weaknessMay follow the pattern of one nerve rootNot a typical feature
Straight leg raise testOften brings on leg painOften normal

This is a simplified summary, based on the NHS, NICE and systematic reviews.[1][3][8][13] Symptoms often overlap, and some people have problems in both the spine and the buttock at the same time.[3]

How it is diagnosed

There is no agreed single test, and no agreed set of criteria.[6][8] Diagnosis is based on your symptoms and examination, after other causes have been looked for.[12][15]

Examination

Your doctor or physiotherapist will usually examine your back, hips and legs, and check the nerves in your legs. They may press deep in the buttock and test hip movements that stretch the piriformis, such as bending the hip, bringing the knee across the body and turning the hip inwards. This is called the FAIR test, from flexion, adduction and internal rotation.[29]

Results for these tests vary. In one study of 33 people, two seated piriformis tests together picked up about 9 in 10 people with nerve entrapment in the buttock, while the straight leg raise picked up fewer than 2 in 10.[13] But a systematic review concluded that the accuracy of the symptoms and tests cannot yet be judged from the studies available, and that a normal straight leg raise does not rule the condition out.[8]

Scans and other tests

  • MRI of the lower spine helps rule out a slipped disc or narrowing of the spine. NICE advises against routine scans in a non-specialist setting such as a GP surgery, and suggests a scan in a specialist setting only if the result is likely to change your treatment.[30] See our MRI guide.
  • MRI of the pelvis and buttock, sometimes with a detailed nerve technique called MR neurography, is used in some specialist centres to look at the sciatic nerve and anything pressing on it.[14][15] A 2024 review felt there is not yet enough evidence to make these scans a standard test.[6]
  • Nerve conduction tests can help rule out other nerve problems, but there is no well-accepted test that confirms piriformis syndrome.[6]
  • A diagnostic injection of local anaesthetic into or around the muscle, guided by a scan. If numbing the area eases the pain, that points to the buttock as the source, and the injection may give some relief too.[14][12]

Treatment

NICE has not published guidance on piriformis syndrome itself. A 2023 systematic review advised following general guidance on back pain and sciatica for first treatment, which means physiotherapy, and found the evidence too weak to recommend one treatment over another.[16]

Exercise, physiotherapy and self-help

  • Keep moving. For sciatica, the NHS advises carrying on with normal activities as much as possible and starting gentle exercise early.[1] The same approach is generally used for piriformis syndrome.
  • Physiotherapy usually includes stretches for the piriformis and hip muscles, strengthening exercises for the hip and trunk, and advice on activity.[12][16] In many areas you can refer yourself to an NHS physiotherapy (musculoskeletal) service.[1] See our physiotherapy guide.
  • Change what brings on the pain. Avoiding provoking activities is part of standard first treatment.[31] For many people that means breaking up long spells of sitting. NICE’s summary for GPs also notes that pressure from outside, such as sitting on a wallet in a back pocket, can irritate the sciatic nerve.[3]
  • Pain relief. Ask a pharmacist or your GP which painkillers are suitable for you.[1]

The trials of physical treatments are small and short. In one trial of 40 people, two stretching methods both reduced pain over 6 weeks, but there was no untreated group for comparison.[22] In another, 32 people were given either dry needling of the muscle or no treatment while on a waiting list. The needling group had less pain a week later, but longer-term results were not measured.[23]

Injections

If exercise and physiotherapy have not helped enough, a specialist may suggest an injection into or around the piriformis muscle, guided by ultrasound, CT or X-ray. Injections are used both to confirm the diagnosis and to treat the pain.[12][14] The main types are:

  • Local anaesthetic, alone or with a steroid. In a randomised trial of 50 people, pain improved in both groups over 3 months, and adding a steroid gave no extra benefit.[17] A European radiology consensus agreed that local anaesthetic injections near the sciatic nerve give good relief, but the role of adding a steroid is unclear.[19] A 2022 pooled analysis of 16 studies, many of them not randomised, found the combination of the two gave the largest fall in pain.[18] So the sources disagree on whether the steroid adds anything.
  • A toxin injection that relaxes the muscle. A small controlled trial found it eased pain more than a dummy injection when combined with physiotherapy.[20] A 2022 review of 7 studies with 152 people judged the evidence fair for safety, with only mild side effects, but too limited to say how much it helps.[21]

Two small trials compared a steroid injection with shockwave therapy, a treatment that passes sound waves into the muscle. Both treatments helped, with no clear difference between them at 5 weeks in one trial and 12 weeks in the other.[24][25]

Results vary widely. In a large US study with no comparison group, 79 in 100 people improved by at least half with injection and physiotherapy.[29] A review of 13 studies with 508 people found only 3 trials showed a fall in pain large enough to matter to patients, and rated the evidence as low quality.[16]

Surgery

Surgery to release the piriformis tendon and free the sciatic nerve is considered only for the small number of people with persistent pain who have not improved with other treatment.[12][31] It can be done as an open operation or as a keyhole (endoscopic) procedure.[28]

Reviews of surgery report improvement in most people, but almost all the studies are case series without a comparison group:

  • A 2017 review of 28 studies with 481 people found pain improved in all of them, with a low rate of complications.[26]
  • A 2025 review of 17 studies with 386 people found complications in about 13 in 100. The most common were no relief (about 5 in 100), symptoms coming back (about 3 in 100), wound problems or infection (about 2 in 100) and weakness moving the hip outwards (about 2 in 100). No injuries to the sciatic nerve were reported.[27]
  • A 2026 review found no studies that directly compared open and keyhole surgery, so neither can be said to be better.[28]

The evidence and its limits

Most of what is known about piriformis syndrome comes from case series and small trials, often run in a single centre. There is no agreed definition, so different studies may not be looking at the same group of people.[8][16] One neurosurgical review called it a highly controversial diagnosis, but accepted that the muscle may be a source of pain in some people.[7] This is why specialists usually look for a cause in the spine first, and why results of treatment are hard to predict.

When to get help

See your GP if your pain has not improved after a few weeks of home treatment, is getting worse, or is stopping you doing normal activities.[1]

For emergencies, see the red box above. Ask for an urgent GP appointment or call NHS 111 if you have pain and feel hot, cold, shivery or generally unwell, or if severe pain starts suddenly or gets worse quickly.[2] Get medical advice promptly if weakness or numbness in a leg is getting worse, or if you have had cancer and develop new back or buttock pain.[3]

Questions to ask

  • Why do you think my pain comes from the buttock rather than my spine?
  • Do I need a scan of my spine or pelvis, and would it change my treatment?
  • Which exercises should I do, and for how long before we review progress?
  • If I have an injection, is it to confirm the diagnosis, to treat the pain, or both?
  • What would we try next if this does not help?

Frequently asked questions

Is piriformis syndrome the same as sciatica?

Not quite. Sciatica usually means pain from a nerve root being pressed in the lower back, most often by a slipped disc.[1] In piriformis syndrome the same nerve is thought to be irritated further down, in the buttock. NICE lists it as one of the conditions that can be mistaken for sciatica.[3]

Why does it hurt more when I sit?

Sitting puts pressure on the buttock, close to where the sciatic nerve passes the piriformis muscle. Pain on sitting is one of the four features that reviews found most often.[9][8] Breaking up long spells of sitting, and not sitting on a wallet in a back pocket, may help.[3]

Will a scan show piriformis syndrome?

Usually not directly. A scan of the lower spine is mainly used to rule out a slipped disc or narrowing of the spine, and only when the result is likely to change treatment.[30] Some specialist centres use MRI of the pelvis to look at the nerve, but a 2024 review felt there is not yet enough evidence to make this a standard test.[14][6]

How long does piriformis syndrome last?

There are no good studies of how long it lasts without treatment. In one large US study, 79 in 100 people improved by at least half with injection and physiotherapy, followed for about 10 months on average.[29] That study had no comparison group, so it cannot show how many would have improved anyway.

Do I need an injection?

Most people start with exercise and physiotherapy.[16] An injection may be offered if these have not helped enough, or to help confirm that the pain is coming from the buttock.[12][14] Studies suggest local anaesthetic injections help many people, but they disagree on whether adding a steroid gives extra benefit.[17][18][19]

Can I keep exercising or playing sport?

Staying active is generally encouraged.[1] Your physiotherapist can help you adjust activities that bring on the pain while you build up your exercises.[31] See our sport and exercise guide.

Further reading

References

  1. NHS. Sciatica. NHS website; page last reviewed 3 December 2024. Link
  2. NHS. Back pain. NHS website; page last reviewed 5 March 2026. Link
  3. National Institute for Health and Care Excellence. Clinical Knowledge Summaries: Sciatica (diagnosis; differential diagnosis). Last revised August 2026. Link
  4. Tomaszewski KA, Graves MJ, Henry BM, et al. Surgical anatomy of the sciatic nerve: a meta-analysis. J Orthop Res. 2016;34(10):1820-1827. Link
  5. Poutoglidou F, Piagkou M, Totlis T, Tzika M, Natsis K. Sciatic nerve variants and the piriformis muscle: a systematic review and meta-analysis. Cureus. 2020;12(11):e11531. Link
  6. Lo JK, Robinson LR. Piriformis syndrome. Handb Clin Neurol. 2024;201:203-226. Link
  7. Halpin RJ, Ganju A. Piriformis syndrome: a real pain in the buttock? Neurosurgery. 2009;65(4 Suppl):A197-202. Link
  8. Hopayian K, Danielyan A. Four symptoms define the piriformis syndrome: an updated systematic review of its clinical features. Eur J Orthop Surg Traumatol. 2018;28(2):155-164. Link
  9. Hopayian K, Song F, Riera R, Sambandan S. The clinical features of the piriformis syndrome: a systematic review. Eur Spine J. 2010;19(12):2095-2109. Link
  10. Kean Chen C, Nizar AJ. Prevalence of piriformis syndrome in chronic low back pain patients. A clinical diagnosis with modified FAIR test. Pain Pract. 2013;13(4):276-281. Link
  11. Batool N, Azam N, Moafa HN, et al. Prevalence of piriformis syndrome and its associated risk factors among university students in Pakistan: a cross-sectional study. BMJ Open. 2025;15(1):e092383. Link
  12. Martin HD, Reddy M, Gómez-Hoyos J. Deep gluteal syndrome. J Hip Preserv Surg. 2015;2(2):99-107. Link
  13. Martin HD, Kivlan BR, Palmer IJ, Martin RL. Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region. Knee Surg Sports Traumatol Arthrosc. 2014;22(4):882-888. Link
  14. Hernando MF, Cerezal L, Pérez-Carro L, Abascal F, Canga A. Deep gluteal syndrome: anatomy, imaging, and management of sciatic nerve entrapments in the subgluteal space. Skeletal Radiol. 2015;44(7):919-934. Link
  15. Kizaki K, Uchida S, Shanmugaraj A, et al. Deep gluteal syndrome is defined as a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2020;28(10):3354-3364. Link
  16. Hopayian K, Mirzaei M, Shamsi M, Arab-Zozani M. A systematic review of conservative and surgical treatments for deep gluteal syndrome. J Bodyw Mov Ther. 2023;36:244-250. Link
  17. Misirlioglu TO, Akgun K, Palamar D, Erden MG, Erbilir T. Piriformis syndrome: comparison of the effectiveness of local anesthetic and corticosteroid injections: a double-blinded, randomized controlled study. Pain Physician. 2015;18(2):163-171. Link
  18. Hilal FM, Bashawyah A, Allam AE, et al. Efficacy of botulinum toxin, local anesthetics, and corticosteroids in patients with piriformis syndrome: a systematic review and meta-analysis. Pain Physician. 2022;25(5):325-337. Link
  19. Sconfienza LM, Adriaensen M, Albano D, et al. Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR), part VII, nerves of the lower limb. Eur Radiol. 2022;32(3):1456-1464. Link
  20. Fishman LM, Anderson C, Rosner B. BOTOX and physical therapy in the treatment of piriformis syndrome. Am J Phys Med Rehabil. 2002;81(12):936-942. Link
  21. Koh MM, Tan YL. Use of botulinum neurotoxin in the treatment of piriformis syndrome: a systematic review. J Clin Orthop Trauma. 2022;31:101951. Link
  22. Shahzad M, Rafique N, Shakil-Ur-Rehman S, Ali Hussain S. Effects of ELDOA and post-facilitation stretching technique on pain and functional performance in patients with piriformis syndrome: a randomized controlled trial. J Back Musculoskelet Rehabil. 2020;33(6):983-988. Link
  23. Tabatabaiee A, Takamjani IE, Sarrafzadeh J, Salehi R, Ahmadi M. Ultrasound-guided dry needling decreases pain in patients with piriformis syndrome. Muscle Nerve. 2019;60(5):558-565. Link
  24. Ahadi T, Yousefi A, Sajadi S, Yousefi N, Babaei-Ghazani A. Comparing radial extracorporeal shockwave therapy and corticosteroid injection in the treatment of piriformis syndrome: a randomized clinical trial. J Bodyw Mov Ther. 2023;33:182-188. Link
  25. Fu YS, Shih KS, Lin YT, Hsieh LF, Liu YF, Chen YR. Efficacy of ultrasound-guided piriformis muscle corticosteroid injection versus extracorporeal shockwave therapy in patients with piriformis syndrome: a randomized controlled trial. J Formos Med Assoc. 2026;125(4):391-397. Link
  26. Kay J, de Sa D, Morrison L, et al. Surgical management of deep gluteal syndrome causing sciatic nerve entrapment: a systematic review. Arthroscopy. 2017;33(12):2263-2278. Link
  27. Garden AR, Finerty JT, Everhart JS. Evaluation of the complications and outcomes of endoscopic and open surgical treatment of piriformis syndrome: a systematic review. J Am Acad Orthop Surg. 2025;33(15):e878-e887. Link
  28. Warman FI, Sedar JAMD, Mahyuddin MH, Harvey W. Endoscopic vs open surgeries for piriformis syndrome: a systematic review and meta-analysis. Adv Orthop. 2026;2026:5126019. Link
  29. Fishman LM, Dombi GW, Michaelsen C, et al. Piriformis syndrome: diagnosis, treatment, and outcome, a 10-year study. Arch Phys Med Rehabil. 2002;83(3):295-301. Link
  30. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management (NG59). Published 30 November 2016, last updated 29 July 2026. Link
  31. Park JW, Lee YK, Lee YJ, et al. Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain. Bone Joint J. 2020;102-B(5):556-567. Link

This article is general information and is not a substitute for advice about your own situation. Please speak to your GP or specialist before making any change to your treatment.

Last checked: October 2026