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Is it sciatica or piriformis syndrome?

Both can send pain from the buttock down the back of the leg, and both get lumped together as 'sciatica' in everyday language. Sciatica from the spine is irritation of a nerve root in the lower back, most often from a disc. Its symptoms often follow the strip of the leg that nerve root supplies (a dermatome), in more involved cases with changes in reflexes, strength, or sensation, and it can occur with or without much back pain. Piriformis syndrome, now often discussed under the broader heading of deep gluteal syndrome, is compression or irritation of the sciatic nerve in the buttock itself, below the spine. Same nerve, different location. The leg symptoms can look similar, and the history, what provokes the pain, and the exam findings help tell them apart. Neither a pain map nor a single nerve-tension test establishes the source on its own.

Written by Kareem Hassanein, Registered Physiotherapist. Burlington, Ontario. This is a guide, not a diagnosis. A brief in-person exam sorts these out reliably.

Side by side

The patterns that separate sciatica from piriformis syndrome in clinic. Read across each row and compare.

Where the pain starts

Sciatica

Often in the low back or sacral area first, then travels down the buttock and leg, although leg pain from a nerve root can come with little or no back pain. Many people can draw a line showing the path of the pain down the leg.

Piriformis syndrome

Starts deep in the middle of the buttock, over the piriformis, above the sitting bone. Low back is typically not the primary complaint.

Nerve-type signs in the leg

Sciatica

Numbness, tingling, or weakness in a dermatomal pattern (for example L5 causing weakness lifting the big toe, or S1 causing a reduced ankle reflex). Present in the more clearly radicular cases.

Piriformis syndrome

Numbness and tingling can occur but are usually vaguer and less mappable. Reflex changes and true myotomal weakness are uncommon. If they are clearly present, a spinal source is more likely.

What provokes it

Sciatica

Bending forward, sitting for long periods, coughing or sneezing (because these raise pressure on an irritated nerve root), morning stiffness after lying down.

Piriformis syndrome

Prolonged sitting on a hard seat, crossing the legs, getting up from the car, running, and direct pressure on the deep buttock. Wallet-in-the-back-pocket flares are classic.

How lumbar positions change it

Sciatica

Often shifts with spine positions. In some people, repeated extension (lying on the stomach, standing tall) draws the leg pain back toward the spine, which is a useful sign. Others are aggravated by extension, so this is something I test in the clinic, not a rule to treat yourself by.

Piriformis syndrome

Spinal movements often change the symptom very little. The pain tends to follow sitting pressure, hip rotation and loading of the deep buttock rather than spine position.

Straight leg raise

Sciatica

Classic reproduction of leg pain between roughly 30 and 70 degrees of passive hip flexion. Suggests nerve-root irritation, especially when it reproduces your familiar leg pain rather than just tightness.

Piriformis syndrome

Can be uncomfortable in the buttock, particularly with added internal rotation, but true reproduction of leg pain in the radicular pattern is less consistent.

Local buttock tenderness

Sciatica

The deep buttock can be tender, but often less strikingly than with a buttock source.

Piriformis syndrome

Focal tenderness when I press into the deep buttock near the greater sciatic notch, often reproducing your familiar pain. It is one of the more consistent features reported, although tenderness alone does not confirm the source.

Sitting behaviour

Sciatica

Sitting is often uncomfortable because of the lumbar load, and you may shift position frequently. Leg pain may build with sustained sitting but is not strictly one-sided from seat pressure.

Piriformis syndrome

A specific pattern: pain builds the longer you sit on that cheek, and relief comes from shifting weight to the other side. Long drives and movie seats are common aggravators.

Red-flag screening

Sciatica

New numbness between the legs, new bladder or bowel changes, or severe or rapidly worsening weakness in both legs mean going to emergency now to check for cauda equina syndrome. Pain that suddenly starts down both legs needs contact with a medical clinician today, and a new foot drop or worsening weakness in one leg needs same-day medical assessment. These are rare, but the screen is always part of the first visit.

Piriformis syndrome

Red flags are uncommon from piriformis alone. Persistent deep buttock pain with night pain or systemic symptoms still warrants a broader screen.

What I check in person to separate them

These are the clinical tests I actually run in the first visit. You cannot do them all on yourself reliably, but understanding what they look for helps explain why an in-person exam sorts these so quickly.

1

Straight leg raise (Lasegue)

I lift your straight leg passively while you lie on your back. Reproduction of your familiar leg pain between roughly 30 and 70 degrees points to nerve-root irritation. Tightness only in the hamstring is not a positive test.

2

Slump test

You sit slumped, tuck the chin, and straighten the knee. This tensions the neural system from the spine down. Reproduction of your leg pain is another signal of radicular involvement. It is more sensitive than straight leg raise in some patterns.

3

FAIR test (Flexion, Adduction, Internal Rotation)

With the hip flexed and the knee pulled across the body into internal rotation, the piriformis is stretched against the sciatic nerve. Reproduction of deep buttock pain and sciatic-type referral supports piriformis syndrome.

4

Seated piriformis stretch test

You sit, I passively adduct and internally rotate the flexed hip while palpating over the piriformis. Reproduction of your familiar pain is supportive. In a 2014 clinical study (Martin et al.), the test was fairly specific but only moderately sensitive for sciatic nerve entrapment in the buttock, and more accurate combined with an active piriformis test.

5

Pace sign (resisted hip abduction and external rotation in sitting)

Resisted contraction of the piriformis from a seated position reproduces deep buttock pain when the muscle is irritable. Useful alongside palpation and the FAIR test rather than as a standalone.

6

Neurological screen (reflexes, myotomes, dermatomes)

Ankle and knee reflexes, big-toe extension and plantarflexion strength, and sensation mapping help identify a specific nerve root. Clear deficits in a nerve-root pattern point toward a spinal source rather than the buttock.

Which pattern fits you better?

Plain-language routing. This is not a diagnosis, and real patients often sit between the two, but the language below is a reasonable starting point.

More likely

Sciatica

Your pattern more closely matches sciatica if the pain started in the low back or the sacral area before spreading down the leg, it follows a clean strip down the leg rather than sitting in the buttock, coughing or sneezing makes it worse, and you have objective nerve signs like dermatomal numbness, a reduced reflex, or big-toe weakness. Bending forward provokes it and lying down or repeated extension often eases it over minutes. A recent bend-and-lift episode, a long drive, or a gradual onset over a few days is a common setup.

Read the sciatica page
More likely

Piriformis syndrome

Your pattern more closely matches piriformis syndrome if the pain is centred in the deep buttock rather than the back, sitting on that side for any length of time flares it, direct pressure into the deep buttock reproduces your familiar pain, and spinal movements do not really change anything. Objective nerve-root signs are absent or vague. A recent increase in running volume, new long drives, a new bike fit, or sitting on a thick wallet are common triggers.

Read the piriformis syndrome page

If you still cannot tell

These two can look similar on the surface, and a smaller share of sciatic-type pain is thought to come from a non-discogenic source in the deep gluteal region. The history and exam help narrow it down. I run the neurological screen first, then the tension tests (straight leg raise and slump), then the piriformis-specific tests (FAIR, seated piriformis stretch, Pace, deep palpation). If the neurological screen is clear and the piriformis tests reproduce your familiar pain, piriformis syndrome moves up the list. If the neurological screen shows dermatomal numbness, a lost reflex, or clear myotomal weakness, the spine is the more likely source and I plan around that. Sometimes the pattern stays uncertain, and I reassess as you respond or flag it for medical investigation. MRI is usually not needed to start treatment. With progressive neurological loss, red-flag features, or symptoms that are not changing on the expected timeline, I flag it to your family doctor or specialist and refer you.

When both are going on

Both can coexist, and a long-standing low back problem can sit alongside deep gluteal irritability. A person with a previous disc episode can later develop piriformis-dominant symptoms, and someone with long-standing piriformis pain can eventually pick up secondary low-back stiffness. That is why I screen the lumbar spine, SI joint, hip, and deep gluteal region on the first visit rather than assuming the label.

When to see a doctor first

  • New trouble starting to pass urine or feeling it pass, new loss of bladder or bowel control, new numbness between the legs or around the back passage, new loss of genital sensation or sexual function, or severe or rapidly worsening weakness in both legs. Go to emergency now. These can be signs of cauda equina syndrome.
  • Pain that suddenly starts down both legs, or spreads from one leg to both, even without the signs above. Contact a medical clinician today for a same-day assessment.
  • A new foot drop (the foot catches or slaps when you walk), or weakness in one leg that is getting worse. Same-day medical assessment.
  • Sudden unexplained weakness or numbness in an arm or leg, even if it improves. Call 911 now. This can be a stroke. Do not wait for a physiotherapy appointment.
  • Fever, unexplained weight loss, a history of cancer, or constant pain at night that does not ease with rest. See your family doctor before starting physiotherapy.

Questions patients ask about telling these apart

My doctor said I have sciatica. Could it actually be piriformis syndrome?

Possibly. 'Sciatica' is often used as a general label for any leg pain that travels down from the buttock, which includes both nerve-root irritation from the spine and sciatic nerve irritation in the deep gluteal region. A focused exam helps tell them apart. If the low back is not tender, spinal movements do not change the symptom, and pressing into the deep buttock reproduces your familiar pain, piriformis or deep gluteal involvement moves up the list.

Do I need an MRI to find out which one it is?

Usually no. MRI is useful when there are progressive neurological signs, red-flag features, or when symptoms are not responding on the expected rehab timeline. For many people, a careful history and exam give enough information to start treatment, with reassessment if the response is not as expected. Imaging also picks up incidental findings in pain-free adults very often, so it is not a shortcut to a diagnosis.

Why does sitting make piriformis pain so much worse?

The sciatic nerve runs either under or through the piriformis muscle, right at the greater sciatic notch. Sitting compresses the nerve and the surrounding deep gluteal structures against the chair, which irritates the tissue further if the muscle is already guarding. That is why soft seats, shifting weight frequently, and breaking up long drives help more than stretching alone in the short term.

Will stretching my piriformis fix it?

Stretching alone is often not enough. A short window of gentle nerve glides and piriformis stretching can calm things, but the sustainable plan usually includes strengthening the gluteus medius and deep hip rotators, changing the loading that set it off (long sitting, running volume, bike fit, wallet), and sometimes dry needling into the deep gluteal region for symptom relief. Stretching a guarding muscle without changing its job tends to give short-lived results.

Is sciatica dangerous?

Most sciatica is not dangerous and settles with time and targeted rehab. Go to emergency now, rather than booking a physiotherapy visit, for new trouble starting to pass urine or feeling it pass, new loss of bladder or bowel control, new numbness between the legs or around the back passage, new loss of genital sensation or sexual function, or severe or rapidly worsening weakness in both legs. These can be signs of cauda equina syndrome. Contact a medical clinician today if pain suddenly starts down both legs or spreads from one leg to both, even without those signs. A new foot drop or worsening weakness in one leg needs same-day medical assessment. Sudden unexplained weakness or numbness in an arm or leg, even if it improves, can be a stroke: call 911 now.

How long does each typically take to settle?

Straightforward sciatica from a disc often improves meaningfully over four to twelve weeks of targeted rehab, though tissue healing can take several months even after pain has resolved. Piriformis or deep gluteal pain can improve over several weeks once the provoking loads are changed and strengthening starts, but the research on it is limited and recovery times vary. Longer-standing cases of either take longer, and I reassess rather than push on if progress stalls by about four weeks.

Evidence this page draws on

Sources I lean on when separating these two conditions in clinic.

Deep gluteal syndrome describes extrapelvic sciatic nerve entrapment in the posterior hip and is an important non-discogenic cause of sciatic-type pain. Piriformis syndrome is one pattern within this spectrum.

Martin HD, Reddy M, Gomez-Hoyos J. "Deep gluteal syndrome." Journal of Hip Preservation Surgery 2015; 2(2): 99-107.

In first-contact care, imaging is not routinely offered for low back pain with or without sciatica. Assessment focuses on ruling out serious causes and judging the risk of a slow recovery, and imaging is considered in hospital or musculoskeletal clinic settings only when the result is likely to change management.

National Institute for Health and Care Excellence. "Low back pain and sciatica in over 16s: assessment and management." NICE Guideline NG59, 2016 (updated 2020).

A systematic review identified buttock pain, pain aggravated by sitting, tenderness near the greater sciatic notch, and pain with manoeuvres that tension the piriformis as the most consistent clinical features of piriformis syndrome.

Hopayian K, Danielyan A. "Four symptoms define the piriformis syndrome: an updated systematic review of its clinical features." European Journal of Orthopaedic Surgery & Traumatology 2018; 28(2): 155-164.

Book an assessment

If this page has helped you narrow things down, or if it has left you wanting a proper exam, I see patients at Endorphins Health & Wellness Centre in Burlington. Direct insurance billing is available, and a physician referral is not required.

4631 Palladium Way, Unit 6

Burlington, ON L7M 0W9

(905) 634-6000

Direct billing. No referral needed.

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