What Is Sciatica? Causes of Leg-Radiating Pain and Physiotherapy

That sharp, throbbing pain that starts in the lower back, moves into the buttock and travels down the back of the leg — sometimes reaching as far as the foot — is commonly known as sciatica. Many people think of sciatica as a disease in its own right; in fact, sciatica is not the name of an illness but a symptom brought on by an underlying problem. This article looks at what sciatica is, what it feels like, what causes it, and the role physiotherapy plays in this picture.

What is sciatica?

Sciatica is the name given to pain felt along the path of the sciatic nerve — the longest and thickest nerve in the body. This nerve leaves the lower back, passes through the buttock and runs down the back of the leg, all the way to the foot. One point matters here: sciatica is not a “diagnosis”; it is a symptom. Saying “sciatica” means “there is pain along the path of this nerve” — but the cause of that pain varies from person to person. The right approach is therefore to see sciatica as a result, and to look for the actual cause behind it.

What does sciatic pain feel like?

Sciatic pain has a character of its own. It is usually one-sided — felt in one leg. The pain most often starts in the lower back or the buttock and spreads down the back of the leg, and it can feel sharp, like an electric shock, or throbbing. It is often accompanied by numbness, tingling or slight weakness in that leg. Symptoms can worsen with prolonged sitting, bending forward, coughing or sneezing — because these movements temporarily change the load on the affected nerve. Where exactly the pain starts and where it spreads gives important clues about the underlying cause.

What causes sciatica?

Sciatica is not tied to a single cause; irritation of the sciatic nerve, or of the nerve roots that form it, at any point along the way can produce this picture. The most common cause is irritation or compression of the nerve roots leaving the lower back at the level of the spine — and the most well-known reason behind that is a herniated disc. We look at the role of disc herniation in this picture in detail in Can a Herniated Disc Heal Without Surgery?. Another spinal cause is narrowing of the canal the nerve root passes through. Beyond these, less commonly, the nerve can also be irritated after it leaves the spine, by structures in the hip and buttock region. Yet another possibility is restriction of the nerve’s own freedom of movement, even without an obvious problem in the back — a nerve needs to glide freely within the tissues around it, and when that gliding is disturbed, sciatica-like symptoms can also appear.

Piriformis syndrome: the cause of every sciatica?

One name that often comes up in connection with sciatica is piriformis syndrome — a presentation in which the piriformis muscle, deep in the buttock, is thought to irritate the sciatic nerve. Honesty matters here, though: piriformis syndrome is a far less common cause than is generally assumed. It is held responsible for only a small proportion of true sciatica cases, and its diagnosis remains debated — there is no reliable test that confirms it definitively, and it is usually a conclusion reached by ruling out other causes. These days, a broader frame such as “deep gluteal syndrome” is preferred for buttock-related sciatica, because the nerve can be affected not just by a single muscle but by other structures in that region as well. In short, piriformis is one possibility — but it is not the source of the great majority of sciatica.

Spine, hip, or the nerve itself? How are they told apart?

Understanding where sciatic pain comes from is the key to the right treatment. In spine-related sciatica, the pain usually changes with movements involving the back (bending forward, prolonged sitting, coughing) and often radiates below the knee, even down to the foot. When the picture originates in the hip region, the pain is felt more deeply in the buttock, worsens with sitting and with movements that rotate the hip, and usually does not extend below the knee. In presentations related to restricted movement of the nerve itself, certain stretching or gliding movements can bring the symptoms on. These distinctions are not always clear-cut and can overlap; the definitive distinction only becomes clear through a careful history and physical assessment.

How is it assessed in physiotherapy?

The first and most critical step of physiotherapy in sciatica is understanding where the pain truly comes from — because treatment is shaped entirely by this. The assessment draws on the history of the pain (where it starts, where it spreads, what makes it worse, what eases it), a movement examination and tests that look at how the nerve is functioning. This assessment both distinguishes whether the picture relates to the spine, the hip or the movement of the nerve itself, and screens for symptoms that call for a more careful approach. Without an accurate assessment, the treatment chosen often misses its target.

How is it treated?

Physiotherapy for sciatica cannot be reduced to a single technique; it is a multi-component process shaped by the cause. In the early period, the aim is to manage the pain and keep the person safely active, within what they can tolerate. The components of the process include neural mobilisation techniques that support the free movement of the nerve, manual therapy, direction-based and graded exercise programmes, and education that helps the person understand their condition. One important point: not all of these techniques suit every sciatica. Neural mobilisation, which targets the free movement of the nerve, is very helpful in some presentations but may not be the right first choice in others. This is exactly why treatment is not a set recipe but an individualised plan based on assessment. For an overview of the lower back and the treatment approach, see the Lower Back Pain page.

How are exercises chosen?

In sciatica, there is no single exercise that works for everyone. The right exercise is chosen according to the source of the pain, which movements bring the person relief, and what they can tolerate. A movement in one direction may ease symptoms in one person, while the same movement increases discomfort in another. A poorly chosen exercise can even temporarily worsen some presentations. This is why the exercise programme is based on assessment and continually updated according to the person’s response.

How long does recovery take?

For most people, sciatica is not as permanent a problem as it appears. The great majority of spine-related sciatic pain improves markedly with conservative approaches, without the need for surgery; this improvement most often begins in the first weeks and usually becomes clear within a few months. Even so, not every sciatica improves at the same pace; the course can vary with its source, how long it has been present and the person’s general condition. What matters is knowing that recovery usually follows an up-and-down path, and staying active in the right way throughout.

When is immediate assessment needed?

The great majority of sciatica cases are not dangerous and settle over time. A few rare symptoms, however, call for assessment without delay. If any of the following is present, care should be sought promptly: marked weakness in the leg that keeps progressing; symptoms affecting both legs at once; or changes in bladder or bowel control together with numbness around the back passage and the inner thighs. This last group of symptoms can be the sign of a rare but time-critical condition and should be assessed immediately.

How can recurrence be reduced?

Sciatica can recur when the underlying cause has not been fully addressed. Reducing recurrences usually comes down to keeping the back and the muscles that support the trunk regularly strong, avoiding long periods of inactivity, and reviewing everyday habits that strain the nerve. This is also where physiotherapy makes its most lasting contribution: not just settling the current episode, but building the kind of resilience that lowers the chance of sciatica returning.

References

• Sciatica — StatPearls / NCBI
• Deep gluteal syndrome: an overlooked cause of sciatica — British Journal of General Practice (2019)
• Neural Mobilization for Lumbar Radiculopathy: Systematic Review & Meta-Analysis — PMC (2023)
• Conservative management of radicular pain in lumbar disc herniation — ScienceDirect (2025)