Sciatica Explained: Causes, Symptoms and What Treatment Involves
Medically reviewed by Kim Le on
Sciatica is one of the most searched conditions we treat, and one of the most misunderstood. The single most useful thing to know at the outset is that sciatica is not a diagnosis. It is a description of where pain travels.
The sciatic nerve is the largest nerve in the body. It forms from nerve roots in the lower back, runs through the buttock and down the back of the thigh, and divides below the knee to supply the lower leg and foot. When something irritates that nerve or the roots that form it, pain follows its path — and that pattern is what people mean by sciatica.
What matters clinically is what is doing the irritating.
What causes it
Lumbar disc herniation. The most common cause, particularly under 50. The outer wall of a disc bulges or tears and its contents press against or chemically irritate a nearby nerve root. Despite how alarming that sounds, most disc herniations reduce over time without intervention.
Lumbar spinal stenosis. More common over 60. Age-related bony and ligamentous changes narrow the space the nerves pass through. The distinguishing feature is that symptoms build with walking or standing and are relieved by sitting or leaning forward — people describe finding themselves leaning on a shopping trolley.
Spondylolisthesis. One vertebra slips slightly forward on the one below, narrowing the exit space for the nerve.
Piriformis syndrome. The sciatic nerve passes beneath, or occasionally through, the piriformis muscle deep in the buttock. Tension there can irritate the nerve. This produces sciatic-type pain without any spinal cause, and it is more often diagnosed than genuinely present.
Less common causes. Pregnancy, pelvic masses, infection, and inflammatory conditions can all produce sciatic pain. These are why assessment includes questions that appear unrelated to your back.
What it actually feels like
Genuine sciatic pain has a recognisable character:
- It travels in a line, usually from the buttock down the back of the thigh, often past the knee
- It is frequently described as burning, electrical, shooting or like a hot wire, rather than aching
- It is usually one-sided
- It often comes with pins and needles or numbness in part of the leg or foot
- Coughing, sneezing or straining commonly makes it briefly worse
- Sitting is often the worst position; walking is sometimes better than standing still
Pain that stops at the buttock, or aches vaguely across the whole leg without following a line, is frequently something other than true sciatica — usually referred pain from a joint in the lower back or pelvis. It matters, because the two respond to different things.
What treatment involves
Assessment first, and it should be thorough. That means establishing which nerve root is involved by testing sensation, power and reflexes in the leg; working out whether the picture fits a disc, stenosis or something else; and screening for the red flags below.
For mechanical sciatica, care typically combines:
Manual therapy and movement. Restoring movement to the segments that are restricted, and finding the positions and movements that reduce your symptoms. Most people have a directional preference — a movement that eases the leg pain — and finding it is one of the more valuable things a first appointment produces.
Graded exercise. Progressive loading, adjusted as symptoms allow. This is what drives recovery over weeks.
Load management. Sitting tolerance, driving, lifting, and how to get through a working day without provoking it.
Co-management where needed. For severe pain, medical management alongside manual therapy is often the sensible combination, and we will say so.
What treatment cannot do
Being straight about this matters.
Manual therapy does not “put a disc back in”. Discs do not slip in and out of place, and no adjustment repositions one. What manual therapy can reasonably do is reduce pain, restore movement, and improve function while the natural resolution of the disc problem takes its course — which it usually does.
For spinal stenosis, the bony narrowing is structural and does not reverse. Treatment aims at function and symptom control, and for some people surgical opinion is the right path.
Anyone promising to cure sciatica in a set number of visits is telling you something the evidence does not support.
Cauda equina syndrome — this is a surgical emergency. Go to an emergency department immediately if you have:
- Numbness or altered sensation around the groin, genitals, buttocks or inner thighs — the area that would contact a saddle
- Difficulty starting or stopping urination, loss of bladder control, or not feeling when you need to go
- Loss of bowel control
- New or worsening weakness in both legs
- Sexual dysfunction of sudden onset
These signs mean the nerve bundle at the base of the spine may be compressed, and delay risks permanent damage. Do not wait for an appointment.
Also see a GP promptly for progressive weakness in one leg, such as a foot that catches when you walk; sciatica with fever, unexplained weight loss or a history of cancer; or sciatica following significant trauma.
What to expect
Most sciatica improves. The typical course runs over four to twelve weeks, and it is rarely a straight line — good days followed by setbacks are the norm rather than a sign that something has gone wrong.
If your leg pain is not improving after six weeks of appropriate care, or if weakness is developing at any point, that is the trigger for further investigation rather than more of the same treatment.
Our team assesses sciatica regularly at both Marrickville and Wetherill Park, and part of that assessment is being honest about when you need a GP, imaging or a specialist opinion rather than us.
Common questions
- Is sciatica a diagnosis?
- Not really. Sciatica is a description of a symptom pattern — pain travelling along the sciatic nerve. The diagnosis is what is irritating the nerve, which is usually a disc, sometimes bony narrowing, and occasionally something else entirely.
- How long does sciatica take to go away?
- Most cases improve substantially over four to twelve weeks, and the majority resolve without surgery. Improvement is often uneven, with good and bad days, which is normal and not a sign of relapse.
- Should I rest or keep moving with sciatica?
- Keep moving within tolerance. Prolonged bed rest makes outcomes worse, not better. That does not mean pushing through severe pain — it means staying as active as the pain reasonably allows and avoiding the positions that clearly aggravate it.
- Can a chiropractor help sciatica?
- For sciatica caused by mechanical irritation of a lumbar nerve root, manual therapy combined with graded exercise and load management can help with pain and function. It cannot reverse a structural narrowing, and any presentation with progressive weakness or the red-flag features below needs medical assessment first.
