What Causes Sciatica (and Why the Buttock Hurts)

The strange part, people say, is that the back barely hurts. It is the buttock that complains: a deep, hot ache on one side that sharpens when you sit, cough, or swing a leg out of the car. Some describe a line of electricity tracking down the back of the thigh; others feel the calf go oddly cool and tingly, like a limb that fell asleep and never fully woke.

That mismatch, pain landing far from where the problem lives, is the whole story of sciatica. The trouble almost always begins in the lower spine. The nerve simply carries the message downstream, so the buttock and leg take the blame for something happening a hand-width higher.

Understanding that wiring changes how you think about the condition. It explains why an X-ray of the hip looks fine, why leaning forward eases some people and worsens others, and why the most useful first step is usually not a scan but a clear-eyed look at what is pressing on what.

What is sciatica, exactly?

Sciatica is not a disease. It is a description of pain that follows the path of the sciatic nerve, the thickest nerve in the body, roughly the width of a finger where it leaves the pelvis, according to Cleveland Clinic. The name tells you where it hurts, not why.

The nerve itself is assembled from five smaller nerve roots that exit the lower spine: two from the lumbar vertebrae and three from the sacrum, the triangular bone at the base of the spine. Those roots bundle together deep in the pelvis, pass behind the hip joint, run under the gluteal muscles, and travel down the back of the thigh before dividing behind the knee to supply the calf, foot, and toes.

Pressure or inflammation anywhere along that route can produce the classic pattern: pain, burning, tingling, numbness, or weakness on one side, radiating from the buttock toward the foot. Mayo Clinic notes that true sciatica almost always affects a single leg, and that the leg symptoms are typically worse than any back pain.

Clinicians often prefer the term lumbar radiculopathy, which means an irritated nerve root in the lower back. It is a mouthful, but it is more honest. The word points at the real culprit, the spine, rather than the messenger.

What causes sciatica most often?

A herniated disc. Every major source, from the NHS to Mayo Clinic, lists it first, and for good reason: the geometry of the lower spine makes it almost inevitable that a bulging disc will meet a nerve root.

Picture the discs as jam doughnuts stacked between the vertebrae. Each has a tough fibrous rim and a soft, gel-like center. With age, load, or a sudden twist under weight, the rim can weaken and let some of that inner gel push outward. The nerve roots exit the spinal canal just beside the discs, so a bulge at the L4/L5 or L5/S1 level, the two lowest discs, tends to press directly on the roots that feed the sciatic nerve.

Pressure is only half of the mechanism. Disc material that escapes its normal boundary also triggers an inflammatory response, releasing chemicals that make the nerve root exquisitely sensitive. This is why a fairly small herniation can produce severe leg pain, and why a large one seen on a scan sometimes causes surprisingly little. Inflammation, not just squashing, drives much of the misery.

Herniated discs cluster in working-age adults, when the disc still has enough gel to bulge. In older adults, the picture shifts toward the causes covered below, where bone and ligament rather than disc material do the pressing.

Why does sciatica hurt in the buttock and not the back?

Because nerves report location badly. A nerve root irritated at the spine does not send a signal that says “problem at the lower back.” It fires along its full length, and the brain interprets that activity as pain wherever the nerve normally gathers sensation: the buttock, the back of the thigh, the outside of the calf, the top or sole of the foot.

The buttock takes the brunt for two practical reasons. First, it is the first stretch of territory the newly formed sciatic nerve passes through after leaving the pelvis, sitting under the gluteal muscles and close to bone. Second, it is where you put your weight when you sit. Sitting rounds the lower back, increases pressure inside the discs, and stretches the nerve over the back of the pelvis at the same time. Many people can stand and walk more comfortably than they can sit in a car.

The pattern also explains a common misunderstanding. People assume a hip problem because the pain is near the hip, or a hamstring strain because the thigh aches. The tell is the map: sciatic pain tends to travel in a line and is often paired with tingling or numbness, sensations that muscles and joints do not produce.

Johns Hopkins Medicine describes this radiating quality as the hallmark that separates sciatica from ordinary low back pain, which stays local and dull rather than shooting.

Why did I suddenly develop sciatica?

Sudden onset is common, and it rarely has a single dramatic cause. Most people can point to a moment, lifting a suitcase, twisting to reach the back seat, a long drive, but the disc that gave way was usually years in the making.

Disc walls lose water content and elasticity gradually through adult life. Micro-tears accumulate without symptoms. Then an ordinary movement adds just enough pressure to push gel through a weakened spot, and inflammation follows within hours. The trigger looks trivial because the structure was already close to its limit.

Other common setups, described by Mayo Clinic and the NHS, include:

• A period of unusually heavy or repetitive lifting, especially with twisting
• Long stretches of sitting, such as travel or a new desk job, which load the lower discs
• A minor fall or jolt, which may shift disc material or inflame a joint that was already narrowing
• Pregnancy, when hormonal changes loosen ligaments and posture shifts the load on the lower spine

Occasionally there is no trigger at all. Waking with sciatica after an uneventful day is a familiar story, and it does not mean something sinister happened overnight. It usually means the inflammatory phase of a small herniation peaked during sleep, when the disc rehydrates and swells slightly.

The reassurance here is real: the abruptness of the pain says very little about how serious the cause is or how long recovery will take.

What other spinal problems cause sciatica?

When the disc is not the culprit, the spine still usually is. Three conditions account for most of the remainder, and they share a theme: less room for the nerve.

Spinal stenosis is a narrowing of the canal or the side openings through which nerve roots exit. Thickened ligaments, enlarged facet joints, and bony spurs crowd the space over decades. It is the leading cause of sciatica in older adults, and it has a signature: symptoms worsen with standing and walking and ease with sitting or leaning forward, which opens the canal. People with stenosis often say they can shop comfortably as long as they lean on the cart.

Spondylolisthesis means one vertebra has slipped forward relative to the one below it. The shift can pinch the nerve root at the exit point. It may follow a stress fracture in adolescence, or develop later as the joints wear.

Degenerative disc disease is the everyday wear that thins discs and loads the joints behind them. A flattened disc narrows the exit opening for the nerve, and the roughened joint edges add bone where there was once space.

Rarer causes, which is why clinicians ask about them, include spinal tumors, infections, and fractures, particularly in people with thinning bones. Mayo Clinic lists these alongside the common causes not to alarm, but because a few specific questions and an examination usually rule them out quickly.

Can a muscle cause sciatica? The piriformis question

Sometimes the nerve is irritated after it has left the spine, and the buttock is the scene of the crime rather than a bystander.

The piriformis is a small, flat muscle that runs from the sacrum to the top of the thigh bone, passing directly over, and in some people through, the sciatic nerve. If it spasms or thickens, it can compress the nerve in the buttock. Cleveland Clinic lists piriformis syndrome among the non-spinal causes of sciatica-type pain. Long sitting on a hard surface, a heavy wallet in a back pocket, running on a slope, and a fall onto the buttock are classic setups.

Clues that point to the muscle rather than the disc include pain that is worst right in the buttock and is reproduced by pressing there, discomfort with sitting that eases on standing, and relatively little back pain or coughing-related pain.

Honesty is due here: piriformis syndrome is a controversial diagnosis in the sense that it is hard to confirm. Scans do not show it reliably, and the same symptoms can arise from a disc. Most clinicians treat it as a diagnosis of exclusion, made after the spine has been assessed. What is uncontroversial is that hip and gluteal muscles can contribute to sciatic irritation, and that stretching and strengthening them is a reasonable part of recovery regardless of the exact source.

What can be mistaken for sciatica?

Plenty. The lower back, pelvis, hip, and thigh are crowded with structures that can hurt in overlapping places, and a surprising number of people carry a sciatica label for pain that has nothing to do with the nerve. The table below summarizes the most common lookalikes and the features that usually separate them.

Condition	Where it typically hurts	Distinguishing features
Hip joint arthritis	Groin, front of thigh, sometimes buttock	Stiffness, pain on rotating the hip, no tingling or numbness
Sacroiliac joint pain	One side of the low back and upper buttock	Stays above the knee, worse with standing on one leg or rolling over in bed
Hamstring strain or tendinopathy	Back of thigh, near the sit bone	Follows exertion, tender to touch, no nerve symptoms
Trochanteric bursitis	Outer hip	Painful to lie on that side, tender over the bony point of the hip
Peripheral artery disease	Calf, thigh, or buttock	Cramping with walking that eases with rest, cool or pale foot
Peripheral neuropathy	Both feet, often symmetric	Numbness and burning that start in the toes, no back link

The last two matter most. Cramping leg pain that stops when you stop walking may be a circulation problem rather than a nerve one, and symmetrical burning feet is more typical of neuropathy, which the NIH links to conditions such as diabetes. Both warrant their own assessment.

A useful home distinction: true sciatica usually radiates below the knee, follows a line, and comes with altered sensation. Pain that stays in the buttock or thigh and behaves like a sore muscle often is one.

Who is most likely to get sciatica?

Nearly half of us, over a lifetime. Cleveland Clinic estimates that about 40 percent of people in the United States experience sciatica at some point. That makes it less an unlucky diagnosis than a common consequence of walking upright on a spine that bends.

Certain factors tilt the odds, according to Mayo Clinic:

• Age. Discs herniate most in the middle decades; stenosis and bone spurs take over later.
• Body weight. Extra load increases mechanical stress on the lower discs.
• Occupation. Jobs that involve twisting, lifting, or long driving raise the risk.
• Prolonged sitting. Sedentary routines are associated with more sciatica than active ones.
• Diabetes. High blood sugar over time can damage nerves and make them more vulnerable.

Smoking appears on several lists as well, because it impairs blood supply to the discs and speeds their degeneration.

None of these is destiny. Plenty of lean, active, non-smoking people herniate a disc reaching for a sock, and many people with every risk factor never do. The list is most useful in reverse: it tells you what to adjust once you have recovered, so the next episode is less likely or less severe.

One honest caveat about weight: it is a mechanical factor among several, and the evidence supports moving more and lifting better as the actionable steps. Blame is neither useful nor accurate.

How long does sciatica last?

Shorter than most people fear, longer than anyone wants. The NHS advises that sciatica usually gets better within four to six weeks, though it can persist longer. Mayo Clinic similarly notes that most people recover with self-care measures within weeks.

The biology behind that timeline is encouraging. The body treats escaped disc material as debris and gradually reabsorbs it, while the inflammatory chemicals that sensitize the nerve settle over the same period. Follow-up scans often show herniations shrinking or disappearing on their own. The nerve, once the pressure eases, typically recovers its normal function, though numbness and tingling can linger for weeks after the pain has faded.

Recovery is rarely a straight line. A good day followed by a flare after a long drive does not mean you have gone backward; it means the nerve is still irritable. What matters is the trend over two or three weeks, not any single afternoon.

Roughly one person in several will still have symptoms beyond the six-week mark, and that is the point at which the conversation with a clinician usually shifts. Persistent pain, progressive weakness, or symptoms that interfere with sleep and work justify a fuller assessment and, for some, imaging or a referral. Stenosis, being structural rather than inflammatory, tends to follow a slower and more fluctuating course than a disc herniation.

How can I make sciatica go away?

You cannot force a disc to reabsorb faster, but you can stop making the nerve angrier and give the body the conditions it needs. Three things matter most, and the evidence behind them is consistent across the NHS, Mayo Clinic, and Harvard Health.

Keep moving. This is the counterintuitive one. Bed rest feels logical and is actively unhelpful; the NHS advises carrying on with normal activities as far as possible. Walking, gentle swimming, and short frequent bouts of movement keep the spine’s structures nourished, prevent the stiffness that layers on extra pain, and reassure the nervous system that the leg is safe to use. Start with what you can tolerate and add a little each day.

Applying heat or cold is a reasonable second measure. Cold packs may help in the first days when inflammation peaks; heat often suits the stiff, achy phase that follows. Neither changes the disc, but both can lower pain enough to make movement possible.

The third is position. Find the posture that eases the leg and use it for rest breaks. For many people with a disc herniation that is lying flat with knees bent, or lying face down; for stenosis it is often sitting or leaning forward. Your body will tell you which camp you are in.

Gentle stretches for the hamstrings, hips, and lower back, and simple core-strengthening exercises, can be added as pain allows. A physical therapist can tailor these, and Mayo Clinic notes that physical therapy is a mainstay once acute pain eases.

What not to do with sciatica?

The mistakes people make with sciatica are mostly made out of good intentions. Knowing them in advance saves weeks.

Do not go to bed and stay there. Beyond a day or two, rest weakens the muscles that support the spine and lets the nerve stiffen in its irritated state. Every major guideline now favors staying active over prolonged rest.

Do not sit for hours at a stretch. Sitting increases disc pressure and stretches the nerve across the pelvis. Break sitting every 20 to 30 minutes with a short walk, even in the office. Long drives are a common cause of flares; plan stops.

Do not stretch aggressively into the pain. A gentle hamstring stretch can help. Yanking the leg toward the chest to “free” the nerve usually inflames it further. Stretching should feel like a mild pull, never a jolt of electricity down the leg.

Do not lift with a rounded back or twist while carrying. Bend at the knees and hips, keep the load close, and turn your feet rather than your spine.

Do not assume a scan is the answer. Imaging in the first weeks rarely changes management and often shows age-related findings that were there before the pain and will be there after it. The NHS and Mayo Clinic both reserve early imaging for red-flag symptoms or persistent, worsening cases.

Finally, do not ignore the warning signs discussed below. Sciatica is common and usually benign, which is exactly why the rare exceptions need to be recognized.

What do medicines and injections actually do for sciatica?

They buy time and comfort while the disc and the nerve settle. None of them repairs a herniation, and understanding what each is designed to do makes it easier to have a sensible conversation with the clinician who prescribes them.

Over-the-counter anti-inflammatory pain relievers work by dampening the chemical signals that cause swelling and sensitize the nerve. They can take the edge off pain enough to allow movement, which is the real therapy. Whether they are appropriate depends on your stomach, kidneys, heart, and other medicines, which is why the decision belongs with a pharmacist or clinician.

Medicines developed for nerve pain act differently: they quiet the overactive firing of irritated nerve fibers rather than reducing inflammation. They tend to take days to weeks to show an effect and are usually considered when pain persists beyond the early phase. Short courses of muscle relaxants are sometimes used for spasm in the surrounding muscles.

Steroid injections, given around the irritated nerve root under imaging guidance, deliver a concentrated anti-inflammatory effect exactly where the disc meets the nerve. Mayo Clinic notes they can reduce pain for a period that varies widely, often weeks to a few months, and that the benefit tends to fade as the effect wears off. They are typically reserved for pain that has not settled with time and movement, and they are limited in frequency because of side effects.

Surgery is a last resort in most cases, considered for progressive weakness, loss of bladder or bowel control, or severe pain that has not responded to other measures over several weeks. Every one of these choices is individual, and the prescribing clinician weighs benefits and risks that this article cannot.

When should I see a doctor about sciatica?

Most sciatica does not need urgent care, and knowing that is reassuring. A short list of symptoms, however, changes the picture completely and should send you to an emergency department the same day. The NHS and Mayo Clinic agree on these red flags:

• Sciatica on both sides at once, or weakness or numbness in both legs that is severe or getting worse
• Numbness or tingling around the genitals, anus, or inner thighs, the so-called saddle area
• Difficulty starting to urinate, being unable to urinate, or losing control of bladder or bowels
• Sudden, severe pain following a significant injury such as a fall or a road accident

These can signal compression of the bundle of nerves at the base of the spinal cord, a condition called cauda equina syndrome. It is rare, and it is one of the few genuine emergencies in back pain, because the window for preserving bladder, bowel, and leg function is measured in hours rather than days.

A routine appointment, rather than an emergency, is appropriate when pain has not begun to ease after a few weeks, is worsening despite sensible self-care, keeps you from sleeping or working, or comes with a noticeable weakness such as a foot that slaps or drags when you walk. Unexplained weight loss, fever, a history of cancer, or long-term steroid use alongside new back pain also warrant an earlier check, since they shift the likelihood toward the rarer causes.

A clinician will typically examine your strength, reflexes, and sensation, and ask about the red flags above. For most people, that examination alone is enough to confirm the diagnosis and rule out anything worrying.

Can you prevent sciatica from coming back?

Not with certainty, but you can shift the odds, and the habits that help are the same ones that shorten the current episode.

Regular exercise tops the list. Mayo Clinic emphasizes strengthening the core, the muscles of the abdomen and lower back that stabilize the spine, along with keeping the hips and hamstrings flexible. A spine supported by strong muscles distributes load more evenly across the discs, and a body that moves daily keeps those discs better nourished.

Sitting well matters more than most people assume. A chair with lower-back support, hips and knees at roughly right angles, and a screen at eye level reduce the flexed posture that loads the lower discs. The bigger win, though, is simply sitting less: standing calls, walking meetings, and a timer that gets you up every half hour.

Lifting technique is worth relearning even if you think you know it. Bend the knees, keep the object close, avoid twisting under load, and when something is heavy or awkward, ask for help. Most disc injuries happen at the end of a long day when fatigue erodes form.

Beyond mechanics, the general markers of good health protect the spine too. Not smoking preserves the blood supply to discs. Keeping blood sugar controlled protects nerves. Managing weight where relevant reduces mechanical load. None of these guarantees a pain-free future, and none of them is a moral test. They are simply the levers the evidence identifies, and pulling a few of them is usually enough to make the next episode, if it comes, milder and shorter.

Frequently asked questions

What causes sciatica in the buttock?

Sciatica in the buttock is usually caused by a nerve root being irritated in the lower spine, most often by a herniated disc. The sciatic nerve passes directly under the gluteal muscles after leaving the pelvis, so irritation upstream is felt there first. Less commonly, the piriformis muscle in the buttock can compress the nerve directly, producing pain that is worst on sitting and tender to the touch.

Why did I suddenly develop sciatica?

Sudden sciatica usually reflects a disc that had weakened gradually and finally bulged under an ordinary load such as lifting, twisting, or a long drive. Inflammation around the nerve root builds within hours, so pain can seem to appear from nowhere. Waking with sciatica is common because discs rehydrate and swell slightly overnight. The abruptness of onset does not indicate how serious the cause is.

How can I make sciatica go away?

You can support recovery by staying active, avoiding long periods of sitting, using heat or cold for comfort, and finding rest positions that ease the leg. The NHS advises continuing normal activities as far as possible rather than resting in bed. Gentle stretching and physical therapy help once acute pain eases. Time is the main healer, with most cases improving within four to six weeks.

What can be mistaken for sciatica?

Hip arthritis, sacroiliac joint pain, hamstring injuries, bursitis on the outer hip, peripheral artery disease, and peripheral neuropathy can all mimic sciatica. True sciatica tends to radiate below the knee in a line and comes with tingling or numbness. Pain that stays in the buttock or thigh, or cramping that stops with rest, usually has a different cause and deserves its own assessment.

What should I not do with sciatica?

Avoid prolonged bed rest, hours of uninterrupted sitting, aggressive stretching into the pain, and lifting with a rounded or twisted back. Each of these increases pressure on the disc or irritates the nerve further. Also avoid assuming an early scan is necessary; imaging in the first weeks rarely changes treatment. Do not ignore red flags such as bladder changes or numbness around the genitals.

Is sciatica always caused by a herniated disc?

No. A herniated disc is the most common cause, but spinal stenosis, a slipped vertebra, bone spurs from wear, and the piriformis muscle in the buttock can also irritate the nerve. Rare causes include tumors, infections, and fractures. A clinician usually distinguishes these through your symptom pattern and a physical examination rather than immediate imaging.

How long does sciatica last?

Most sciatica improves within four to six weeks, according to the NHS, though some cases last longer. Recovery often includes good days and setbacks, and numbness or tingling can linger after the pain fades. Pain that persists beyond six weeks, worsens, or comes with progressive weakness warrants a fuller assessment with a clinician.

Does sitting make sciatica worse?

Often, yes. Sitting rounds the lower back and increases pressure inside the discs while stretching the sciatic nerve across the back of the pelvis. Many people find standing and walking more comfortable than sitting, especially in cars. Breaking sitting every 20 to 30 minutes and supporting the lower back can reduce flares. Spinal stenosis is the exception, where sitting typically brings relief.

When is sciatica an emergency?

Seek emergency care the same day if you develop numbness around the genitals or anus, difficulty urinating or loss of bladder or bowel control, weakness or numbness in both legs, or sciatica on both sides at once. These can signal cauda equina syndrome, a rare compression of the nerves at the base of the spine that needs urgent treatment to protect function.

Can sciatica come back after it goes away?

It can, because the underlying disc wear or spinal narrowing does not disappear. Regular core strengthening, flexibility work for hips and hamstrings, good lifting technique, less time sitting, and not smoking are the measures mainstream sources identify as lowering the risk of recurrence. Recurrences are often milder and shorter in people who keep active between episodes.

References

• NHS: Sciatica
• Cleveland Clinic: Sciatica
• MedlinePlus: Sciatica

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.