The sciatic nerve is the largest and longest nerve in the human body. It originates from the lower lumbar and sacral spine, passes through the pelvis and buttock region and extends down the back of each leg to the foot. Because of its length and pathway, the sciatic nerve is particularly vulnerable to compression or irritation at multiple points along its course.

When treatment is delayed, ongoing nerve compression may lead to persistent inflammation and reduced nerve function. Over time, this can result in chronic pain, worsening numbness, muscle weakness, reduced mobility and difficulty performing daily activities. In more severe or prolonged cases, untreated nerve compression may cause long-term neurological deficits that are harder to reverse, even after intervention.

What causes sciatica / nerve compression?

Sciatica occurs when nerves are mechanically stressed, irritated or compressed. Some of the key mechanisms include:

Disc-related causes

• Herniated discs — when disc material protrudes beyond its normal boundary, it can directly press on nearby nerve roots that form the sciatic nerve, triggering radiating leg pain and neurological symptoms.
• Degenerative disc disease — progressive disc dehydration and height loss reduce the space available for nerve roots, increasing their susceptibility to compression during routine spinal movement.

Spinal canal and nerve passage narrowing

• Spinal stenosis — narrowing of the central spinal canal compresses multiple nerve structures, often causing sciatica that worsens with standing or walking.
• Foraminal stenosis — tightening of the openings where nerves exit the spine places focal pressure on individual nerve roots, commonly producing one-sided leg pain or weakness.

Spinal alignment and joint-related causes

• Spondylolisthesis — forward slippage of one vertebra over another alters spinal alignment, reducing nerve space and increasing mechanical irritation of nerve roots.
• Osteoarthritis — degenerative changes in spinal joints may lead to bone spur formation, which can encroach on nerve pathways and cause chronic nerve compression.

Other potential causes

• Pregnancy — postural changes, pelvic widening and fluid-related tissue swelling during pregnancy can temporarily increase pressure on the sciatic nerve.
• Traumatic injuries — falls, accidents or sports injuries can cause disc disruption, fractures or soft tissue swelling that compresses the sciatic nerve or its roots.

Rare but serious causes

• Conus medullaris syndrome — compression near the end of the spinal cord may affect bowel, bladder and lower limb function and requires urgent medical evaluation.
• Cauda equina syndrome — compression of multiple nerve roots at the lower spine can cause severe weakness, numbness in the saddle region and loss of bladder or bowel control, requiring immediate surgical attention.
• Tumours, cysts or other growths — abnormal tissue growth within or near the spine may occupy space needed for nerves, leading to progressive compression symptoms.

What are the symptoms of sciatica / nerve compression?

The condition typically causes the following symptoms:

• Radiating leg pain — pain that travels from the lower back or buttocks down the leg.
• Numbness or tingling — “pins and needles” sensation in the leg or foot.
• Muscle weakness — affecting walking, standing on toes or lifting the foot.
• Lower back pain — often accompanies nerve-related symptoms.
• Aggravation with movement — bending, sitting, coughing or sneezing may worsen symptoms.
• Severe cases — bowel or bladder dysfunction, requiring urgent medical attention.

Who is at risk of sciatica / nerve compression?

Although sciatica and nerve compression are common conditions, certain populations are more vulnerable due to structural or lifestyle factors. This includes:

• Older adults — age-related changes in the spine, such as reduced disc height and joint flexibility, narrow the spaces through which nerves travel, making compression more likely even with everyday movements.
• Athletes or runners — repeated high-load training and muscle tightness around the hips and pelvis can alter normal movement patterns, increasing tension or pressure along the course of the sciatic nerve.
• Individuals with herniated discs — existing disc displacement reduces the margin of space around spinal nerves, meaning even small movements or inflammation can trigger nerve irritation.
• Individuals diagnosed with diabetes — diabetes-related nerve vulnerability and impaired microcirculation reduce nerve resilience, making sciatic nerve irritation more severe or prolonged when compression occurs.
• People with physically demanding jobs — frequent lifting, twisting or sustained physical strain expose the spine to cumulative stress, increasing the likelihood that nerves become irritated or compressed over time.
• Poor posture or sedentary lifestyles — prolonged sitting or habitual slouching places sustained pressure on the lower spine, reducing nerve tolerance and increasing sensitivity to compression.
• Obesity — additional body weight increases mechanical load on the spine and can further narrow nerve exit pathways, lowering the threshold for nerve compression symptoms.
• Tobacco use — smoking impairs blood flow and tissue healing, contributing to disc degeneration and reduced nerve recovery when compression or irritation occurs.

Is sciatica the same as a slipped disc?

Although many patients use the term “slipped disc” interchangeably with sciatica, they are not the same. Sciatica refers to a set of symptoms, typically pain that radiates from the lower back down the buttock and leg due to irritation of the sciatic nerve.

A “slipped disc” (more accurately known as a disc herniation) is one possible cause of this nerve irritation.

How is sciatica / nerve compression diagnosed in Singapore?

Dr James Tan performs a structured evaluation to confirm nerve compression, assess severity and guide treatment. The process entails:

• Clinical history — our doctor begins by identifying triggering events, activity patterns and prior spine or nerve issues.
• Symptom review — this focuses on the pain location, intensity and neurological involvement. Dr James will look for:
  • Radiating leg pain distribution
  • Numbness, tingling or weakness
  • Functional limitations in walking, standing or lifting
• Physical examination — this is performed to evaluate nerve and muscular function, which involves:
  • Straight-leg raise test or other nerve tension tests
  • Muscle strength, reflexes and sensation
  • Posture and gait assessment
• Imaging examination — imaging may be arranged when needed:
  • X-ray — to assess alignment, spondylolisthesis or degenerative changes
  • Magnetic resonance imaging (MRI) — a detailed evaluation of discs, nerve roots and soft tissue
  • Computed tomography (CT) scan — this is typically reserved for complex or unclear cases
• Additional tests — in selected cases, additional investigations may be required to clarify nerve involvement:
  • Nerve conduction velocity (NCV) studies — measure how efficiently electrical signals travel along nerves, helping identify nerve dysfunction and its severity.
  • Electromyography (EMG) — assesses muscle electrical activity to determine whether nerve compression has affected muscle activation or caused ongoing nerve damage.
  • Myelogram — a specialised imaging test using contrast dye to outline the spinal cord and nerve roots, typically used when MRI findings are inconclusive or when surgical planning is required.

How is sciatica / nerve compression treated in Singapore?

The treatment for sciatica and nerve compression focuses on alleviating the pain while increasing mobility. Depending on the severity of the condition, it may include:

Conservative management

• Activity modification — avoiding positions or movements that worsen symptoms.
• Load management — adjusting lifting, bending or exercise routines.
• Pain management — ice, heat or prescribed analgesics to reduce discomfort.
• Education — guidance on posture, ergonomics and safe daily movements.

Non-surgical interventions

• Physiotherapy programmes — targeted stretching, strengthening and neuromuscular control exercises to relieve nerve tension.
• Supportive bracing or taping — temporary relief and improved posture during rehabilitation.
• Epidural steroid injection — used selectively to reduce nerve-root inflammation and relieve severe radiating pain.
• PRP injections — may be considered in selected cases to target inflammation and support healing in disc-related sciatica.
• Nucleoplasty / annuloplasty — percutaneous procedures that address disc-related pain by decompressing the disc or stabilising small tears within the outer disc layer.
• Nerve root injection — an injection placed at the level of the affected nerve to both localise and calm inflammation.
• Radiofrequency ablation — applies thermal energy to interrupt pain transmission along specific nerves.

Surgical management (selected cases)

• Microdiscectomy/decompression — removes disc material pressing on the nerve.
• Spinal fusion or stabilisation — for structural instability or recurrent compression.
• Minimally invasive spine surgery — reduces recovery time and soft tissue disruption.

Rehabilitation and return to activity

• Gradual core and spinal strengthening — improves spinal support, reduces disc load and protects nerve roots.
• Posture correction and movement retraining — restores safe lifting, sitting and standing mechanics.
• Graduated return to work or sport — staged reintroduction based on functional milestones.
• Recurrence prevention strategies — ergonomics, core conditioning and safe exercise guidance.

Book an Appointment

Ongoing leg or back pain can be frustrating, especially when it starts to affect sleep, work or everyday movement. If symptoms such as numbness, tingling or weakness are not settling, it may be a sign that a nerve is being irritated rather than a simple muscle issue.

Booking an appointment with Dr James Tan allows you to understand what is driving your symptoms and receive a clear, step-by-step plan focused on relieving pain, protecting nerve health and helping you return to daily activities with confidence.