Carpal Tunnel Syndrome: Causes, Symptoms, Diagnosis, and Treatment

Carpal Tunnel Syndrome (CTS) is the most common entrapment neuropathy worldwide, now affecting ≈4‑5 % of the population.¹ Modern lifestyle shifts—especially prolonged smartphone, tablet, and computer use combined with increasingly sedentary routines—have pushed CTS incidence upward over the last decade.

Carpal Tunnel Syndrome (CTS) occurs when the median nerve is compressed as it traverses the carpal tunnel—a rigid, ligament‑roofed canal at the wrist. Early hallmark symptoms include nocturnal numbness or tingling in the thumb, index, middle, and radial half of the ring finger. Without timely intervention, chronic compression may lead to persistent sensory loss and then muscle wasting.

The 2024 American Academy of Orthopaedic Surgeons (AAOS) guideline emphasises that CTS is multifactorial.² Key contributors and risk modifiers now recognised include:

• Repetitive wrist/finger motions (typing, data entry, production‑line work, knitting, gaming).
• Prolonged daily smartphone or tablet use (>2 h/day) with the wrist in sustained flexion and high‑thumb activity.³ ⁴
• Extended computer use (>10‑12 h/day) in ergonomically sub‑optimal setups (keyboard too high, wrist extension).
• Sedentary lifestyle and obesity—BMI ≥ 30 doubles CTS risk via fluid retention and micro‑vascular changes.
• Endocrine & systemic disorders: diabetes, hypothyroidism, rheumatoid arthritis, pregnancy‑related oedema.
• Wrist trauma or structural anomalies (fractures, dislocations, congenital narrow tunnel).
• Genetics—first‑degree relatives with CTS increase personal risk 2‑fold.

Symptoms generally progress slowly:

• Numbness, tingling, or burning pain in the median‑nerve distribution, often waking patients at night.
• Weak grip, hand clumsiness, or object dropping.
• Activity‑related wrist/forearm pain.

Late signs: constant numbness and thenar atrophy.

Diagnosis is clinical, confirmed when needed by nerve conduction studies (NCS) showing prolonged distal motor latency (>4.2 ms) or decreased sensory conduction velocity. Ultrasound > 9 mm² median nerve cross‑sectional area at the tunnel inlet supports the diagnosis, especially in smartphone overuse cohorts.⁴

• First‑line (≤6 weeks): Nocturnal neutral‑position wrist splint + activity modification.
• Evidence‑backed adjuncts: Single ultrasound‑guided corticosteroid injection (strong short‑term relief). Ultrasound therapy & yoga provide modest benefits (moderate evidence).
• Pharmacology: NSAIDs for pain; gabapentinoids & diuretics **not recommended** for isolated CTS.
• Surgery: Endoscopic or mini‑open carpal tunnel release indicated after ≥6 weeks failed conservative care or if severe electrodiagnostic findings. Both methods show similar long‑term outcomes; endoscopic release allows a median 9‑day earlier return‑to‑work.

• Maintain neutral wrist posture; position keyboard low and keep elbows at 90 °.
• Implement the 30‑30 rule: break from keyboard/phone every 30 min for 30 s of wrist and finger stretches.
• Use voice‑to‑text or external keyboards for heavy smartphone users.
• Keep BMI < 25, control blood glucose, stay physically active ≥150 min/week.

With early diagnosis and guideline‑concordant care, >85 % of patients achieve sustained symptom relief. Delayed surgery (fixed numbness >6 months) predicts poorer sensory recovery.