What Is Sciatica & What Causes It?
Sciatica (lumbar radiculopathy, ICD-10 M54.3) is pain that travels from the lower back or buttock down the leg, along the path of an irritated nerve root. It is a symptom, not a diagnosis: the cause is most often a slipped disc, but narrowing of the spinal canal and a slipped vertebra can produce it too.
The sciatic nerve is formed from nerve roots that leave the lower spine and run down the back of each leg. When one of these roots is compressed or inflamed, pain is felt along its course — through the buttock, down the back or side of the thigh and calf, often into the foot.
Common Causes of Sciatica
A disc herniation pressing on a nerve root (Read about slipped disc).
Narrowing around the nerves from wear and tear (Read about canal stenosis).
A vertebra slipped on the one below, narrowing the nerve exit (Read about spondylolisthesis).
Less commonly, sciatica-like pain comes from a spinal tumour or cyst, infection, or problems outside the spine such as the hip or the piriformis muscle. This is why persistent sciatica deserves a proper assessment.
Symptoms, Warning Signs & Diagnosis
Common clinical manifestations of lumbar radiculopathy include:
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Radiating pain: Sharp, burning, or electric pain down one leg, often below the knee.
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Sensory changes: Tingling, pins and needles, or numbness in the leg or foot.
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Motor deficits: Weakness in the leg or foot.
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Positional aggravation: Pain worse with sitting, coughing, or bending.
New difficulty passing urine or controlling the bladder or bowel, numbness around the genitals or buttocks ("saddle" numbness), or rapidly worsening weakness in the legs can indicate cauda equina syndrome — a surgical emergency. Go to the nearest hospital emergency department without delay.
How the Cause Is Found
A careful history and neurological examination usually identify the nerve root involved. An MRI is advised when pain persists beyond several weeks, when there is weakness, or when surgery is being considered, to show what is pressing on the nerve (see common symptoms of spine conditions).
Treatment Options
Treatment of sciatica is tailored to the underlying cause and severity of symptoms:
- Non-surgical care: Medicines for pain and nerve pain, staying active, physiotherapy, and time.
- Injections: An epidural or nerve-root injection in selected patients.
- Surgery: When disabling pain persists or weakness worsens, the operation depends on the cause: microdiscectomy or endoscopic discectomy for a slipped disc; lumbar decompression for stenosis; TLIF for an unstable slip.
Treating sciatica means treating its cause; the same leg pain can need different operations, or none at all. The choice should follow the anatomy of your condition, your own circumstances — your health, your work, and what matters to you in recovery — and the advice of your neurosurgeon after examining you and reviewing your scans.
Questions to Ask Your Spine Surgeon or Neurosurgeon
These are the questions patients most often search for about sciatica:
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Underlying cause: What is causing my sciatica?
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Imaging timing: Do I need an MRI now, or can we wait?
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Prognosis: How long does sciatica usually last?
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Rehabilitation: Which exercises help, and which should I avoid?
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Injections: Is an injection an option for me?
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Surgical indication: When would surgery be the better choice?
Unless there is an emergency, spine surgery is a planned decision. Seeking a second opinion from a qualified spine surgeon or neurosurgeon before deciding is entirely appropriate.
Frequently Asked Questions
General information only. Please consult a qualified spine surgeon or neurosurgeon for advice about your situation.
Sciatica is pain travelling from the lower back or buttock down the leg along the course of an irritated lumbar nerve root, often with tingling or numbness. It is a symptom of nerve compression rather than a diagnosis in itself.
The most common cause is a slipped (herniated) disc pressing on a nerve root. Other causes include lumbar canal or foraminal stenosis, spondylolisthesis, and less commonly tumours, cysts, or infection.
Many episodes of sciatica caused by a disc herniation improve over a few weeks to a few months with non-surgical care. Pain that persists, keeps returning, or is accompanied by weakness should be assessed by a spine specialist.
Yes. Most people with sciatica improve without surgery. Surgery is considered when disabling leg pain persists despite treatment, when weakness is worsening, or urgently when there are signs of cauda equina syndrome.
See a doctor if leg pain is severe, lasts more than a few weeks, keeps coming back, or comes with numbness or weakness. Seek emergency care for bladder or bowel changes, numbness around the genitals or buttocks, or rapidly worsening leg weakness.
Sciatica is often managed first by a family doctor or physiotherapist, with a spine surgeon involved when symptoms persist or weakness develops. Dr Jaydev Panchawagh—MBBS (B.J. Medical College, Pune), MS in General Surgery (KEM Hospital, Pune), and MCh in Neurosurgery (Seth GS Medical College and KEM Hospital, Mumbai)—is a consultant neurosurgeon in Pune (102, Bhagyatara Society, Erandwane, Pune, Maharashtra 411004; Tel: +91-9011333841) who assesses the cause of sciatica and offers surgery when it is needed.
