Low Back Pain: Causes, Diagnosis and Treatment

Low back pain is the world's leading cause of years lived with disability. It affects approximately 80% of adults at some point in their lives and is one of the most common reasons for medical consultation, work absence, and disability retirement globally.

The good news: most episodes of acute low back pain improve significantly within 4–6 weeks with conservative management. But for a significant minority, pain becomes chronic (persisting more than 12 weeks) and may reflect a structural problem requiring more targeted treatment.

Anatomy of the Lower Back

The lumbar spine consists of five vertebrae (L1–L5) stacked between the thoracic spine above and the sacrum below. Between each pair of vertebrae lies an intervertebral disc — a tough fibrous ring (annulus fibrosus) surrounding a gel-like centre (nucleus pulposus) that acts as a shock absorber.

The spinal cord ends at approximately L1–L2, and below this level, a bundle of nerve roots called the cauda equina passes through the spinal canal before exiting through gaps in the vertebrae (foramina) to supply the legs, bladder and bowel.

Structures that can cause low back pain include: vertebral bodies and joints, intervertebral discs, nerve roots, spinal canal contents, paravertebral muscles, ligaments, and referred pain from abdominal or pelvic organs.

Causes

Muscle and Ligament Strain (Mechanical Back Pain)

The most common cause of acute low back pain — typically from sudden awkward movement, heavy lifting, poor posture, or prolonged sitting. There is no structural disc or nerve damage. Pain is usually diffuse, worse with movement, and improves with gentle activity.

Disc Herniation (Slipped Disc)

The nucleus pulposus can bulge or rupture through the outer annulus fibrosus. If the herniated disc material presses on a nerve root exiting the spinal canal, it causes radiculopathy — shooting pain, numbness, tingling or weakness radiating down the leg along the nerve's distribution. This is the classic presentation of sciatica.

The L4–L5 and L5–S1 levels are herniated most commonly. Most disc herniations resolve with conservative treatment within 6–12 weeks as the herniated material retracts and inflammation subsides.

Sciatica

Sciatica describes pain radiating from the lower back or buttock down the leg, following the path of the sciatic nerve (through the back of the thigh, knee, calf and sometimes foot). It is most commonly caused by disc herniation compressing a nerve root, but can also result from spinal stenosis or piriformis syndrome.

Spinal Stenosis

The spinal canal can narrow (stenosis) due to OA-related bone and ligament overgrowth, reducing space for the spinal cord and nerve roots. This produces neurogenic claudication — pain, heaviness and weakness in the legs that worsens with walking and standing, and relieves with sitting or bending forward (flexing the spine widens the canal). It is most common in people over 60.

Degenerative Disc Disease (DDD)

As discs age, they dehydrate and lose height, reducing their shock-absorbing capacity. The vertebrae above and below shift closer together, straining facet joints and ligaments. This is a near-universal process of ageing, but becomes symptomatic when it contributes to nerve compression or mechanical instability.

Spondylolisthesis

Forward slippage of one vertebra over the one below. Most commonly at L4–L5. Can be congenital (isthmic), degenerative (most common in older adults) or post-traumatic. Causes low back pain and, if nerve roots are compressed, leg symptoms.

Facet Joint Arthritis

The facet (zygapophyseal) joints on the back of the spine are true synovial joints susceptible to osteoarthritis. Facet OA causes localised axial back pain, often worse with extension and rotation, and may refer pain to the buttock.

Serious Causes (Red Flags — Require Urgent Assessment)

A small minority of low back pain cases have serious underlying causes. Red flag symptoms that warrant prompt investigation include:

• Age of first onset under 20 or over 55 without a prior history of back pain
• Constant, progressive, non-mechanical pain (not relieved by rest)
• Pain at rest or at night (possible tumour or infection)
• Unexplained weight loss, fever, or night sweats
• History of cancer (possible spinal metastasis)
• Bowel or bladder dysfunction — incontinence, retention, or saddle anaesthesia (numbness in the perineum, inner thighs) — cauda equina syndrome (surgical emergency)
• Significant lower limb neurological deficit (progressive weakness)
• Structural spinal deformity
• Thoracic pain

Diagnosis

Clinical Assessment

The clinician takes a detailed history (onset, character, distribution, aggravating and relieving factors, neurological symptoms, red flags) and examines the spine, hips, and neurological function (reflexes, sensation, muscle power, straight leg raise test).

The straight leg raise test — lifting the leg while the patient lies flat, reproducing the patient's radiating leg pain at less than 60° — is highly sensitive for lumbar disc herniation compressing a nerve root.

Imaging

Important: most acute low back pain does NOT require imaging. Imaging findings (disc bulges, disc degeneration) are common in pain-free adults and do not reliably predict symptoms.

Imaging is indicated when:

• Red flag symptoms are present
• Neurological deficit is progressive or severe
• Conservative treatment has failed after 4–6 weeks
• Surgery is being considered

X-ray — shows vertebral alignment, disc space height, fractures and degenerative changes. Cannot show soft tissue (discs, nerves).

MRI of the lumbar spine — the gold standard for low back pain with neurological features. Clearly shows disc herniations, nerve root compression, spinal stenosis, cord and cauda equina, bone marrow pathology (infection, tumour), and ligament integrity. No radiation.

CT scan — used when MRI is contraindicated (metal implants, claustrophobia) or to assess bony detail (fractures, bone spurs). Higher radiation dose.

CT myelogram — injection of contrast into the spinal fluid followed by CT; used pre-operatively when MRI is unavailable or inadequate.

Treatment

Conservative Management (First-Line)

Active management — staying active is critical. Bed rest is harmful; patients who maintain gentle daily activity recover faster. Walking and gentle stretching are encouraged from day one.

Physiotherapy — structured exercise programmes (core strengthening, flexibility) are the most effective medium-term treatment. Spinal manipulation by physiotherapists or chiropractors may provide short-term relief in acute non-specific back pain.

Analgesia:

• Paracetamol — limited evidence but safe
• NSAIDs (ibuprofen, naproxen, diclofenac) — more effective than paracetamol for acute LBP; use short courses
• Muscle relaxants (diazepam, cyclobenzaprine) — for acute muscle spasm; short-term use only
• Opioids — reserved for severe, short-term use; long-term opioids for chronic LBP are not recommended
• Neuropathic agents (gabapentin, pregabalin, duloxetine) — for radicular pain with neuropathic features

Heat therapy — continuous low-level heat wraps reduce acute back pain and improve function.

Psychological support — chronic low back pain has significant psychological components. Cognitive behavioural therapy (CBT) reduces pain catastrophising and improves function in chronic LBP.

Injections

Epidural corticosteroid injection (ESI) — steroid injected into the epidural space under fluoroscopic guidance. Provides 4–8 weeks of pain relief in disc herniation with radiculopathy; reduces the need for surgery in some patients. Effect is temporary; typically 1–3 injections per year.

Facet joint injections / medial branch blocks — for facet joint pain; diagnostic and therapeutic.

Radiofrequency ablation (RFA) of medial branch nerves — longer-lasting facet pain relief (6–18 months) by heat-destroying the nerves carrying pain from facet joints.

Surgery

Surgery is indicated for:

• Cauda equina syndrome — emergency surgery within hours
• Progressive neurological deficit — worsening leg weakness
• Severe radiculopathy not responding to 6–12 weeks of optimal conservative treatment
• Spinal stenosis causing significant disability

Microdiscectomy (lumbar disc herniation) — minimally invasive removal of the herniated disc fragment through a small incision; the most common elective spinal surgery. Success rate for relief of leg pain (sciatica) exceeds 90%. Most patients are mobilised the same day and discharged within 1–2 days.

Decompressive laminectomy (spinal stenosis) — removal of the lamina and overgrown ligamentum flavum to decompress the spinal canal; relieves neurogenic claudication in 70–85% of patients.

Spinal fusion — joining two or more vertebrae permanently with bone graft and instrumentation (screws, rods, cages). Used for spondylolisthesis, segmental instability, or following extensive decompression. Longer recovery (3–6 months) and mixed evidence for non-specific chronic back pain; generally reserved for cases with clear structural pathology.

Minimally invasive spinal surgery (MISS) — increasingly available; uses tubular retractors and endoscopic techniques to achieve decompression through smaller incisions, with less muscle damage and faster recovery.

Vertebroplasty / kyphoplasty — for painful vertebral compression fractures (osteoporosis); injection of bone cement (vertebroplasty) or balloon inflation followed by cement (kyphoplasty) to stabilise and restore vertebral height.

Spinal Care in China

China's premier spinal surgery centres offer:

• Comprehensive lumbar spine work-up: clinical assessment, standing X-rays, MRI and electrophysiology (EMG/nerve conduction)
• Expert discectomy and decompression: high-volume spinal surgeons performing full endoscopic and minimally invasive microdiscectomy as day-case or overnight procedures
• Complex spinal reconstruction: instrumented fusion, correction of deformity (scoliosis, spondylolisthesis), and revision surgery at internationally competitive standards
• Interventional pain management: CT/fluoroscopy-guided ESI, medial branch blocks, and radiofrequency ablation
• Cost: care in China is generally less expensive than UK private treatment, but the hospital prices each case individually — ask us for the written quote before you commit.
• Full English care navigation throughout assessment, treatment and recovery

Contact a ChinaMedicalTour care navigator to arrange a spinal assessment or surgical consultation.

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Medical content based on MSD Manuals and international spine surgery guidelines. Evidence reviewed 2025.

Frequently Asked Questions

Can international patients get a remote MRI review for joint or spinal conditions before traveling?

Yes. Overseas patients can submit DICOM MRI, CT, or X-ray imaging for remote pre-consultation coordination with Chinese orthopedics and spine specialists to assess surgical vs conservative indications.

What minimally invasive orthopedic procedures are commonly evaluated in China?

High-volume orthopedic departments evaluate arthroscopic joint repair, total joint replacement (hip and knee arthroplasty), percutaneous spinal endoscopy, and structured post-operative physical rehabilitation.

How is hospital admission and post-operative mobility coordinated?

Inpatient observation duration, surgical scheduling, and mobilization milestones are established directly by the hospital care team, supported by bilingual coordination throughout the hospital stay.