Carpal Tunnel Syndrome: Symptoms, Causes & Treatment
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Carpal tunnel syndrome is compression of the median nerve in the wrist causing numbness, pain, and weakness in the hand.
What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome (CTS) is one of the most common peripheral nerve compression disorders, resulting from increased pressure on the median nerve as it passes through the carpal tunnel — a rigid fibro-osseous channel on the palmar side of the wrist. The tunnel floor and walls are formed by the carpal bones, while the transverse carpal ligament forms its roof. The median nerve shares this confined space with nine flexor tendons, making it vulnerable to compression whenever tunnel pressure rises.
Symptoms typically begin insidiously with numbness, tingling, and burning pain in the thumb, index, middle, and radial half of the ring finger — the median nerve's sensory distribution. Nocturnal symptoms are classic, often waking patients from sleep; shaking the hand (Flick sign) provides temporary relief. As CTS progresses, daytime symptoms appear, grip strength weakens, and fine motor tasks such as buttoning or picking up small objects become difficult. Advanced cases show thenar eminence wasting reflecting chronic motor fiber damage.
CTS affects women two to three times more often than men and has a peak incidence between ages 40 and 60. Risk factors include repetitive wrist use, vibrating tools, obesity, pregnancy, hypothyroidism, diabetes, and rheumatoid arthritis. Management ranges from conservative splinting and corticosteroid injections to surgical carpal tunnel release, which carries excellent long-term outcomes for most patients.
Symptoms
- Numbness and tingling in the thumb, index, middle, and radial ring finger
- Nocturnal pain and paresthesias waking the patient from sleep (Flick sign relieves temporarily)
- Grip weakness and difficulty with fine motor tasks (buttoning, pinching)
- Pain radiating up the forearm and occasionally to the shoulder
- Thenar wasting in advanced or longstanding cases
Causes
- Repetitive or forceful wrist motions (keyboard use, vibrating tools, assembly-line work)
- Systemic conditions causing tissue swelling: hypothyroidism, diabetes, rheumatoid arthritis, pregnancy
- Anatomical predisposition: congenitally narrow tunnel, prior wrist fractures (Colles' fracture)
- Space-occupying lesions within the tunnel: ganglion cysts, lipomas
- Fluid retention from pregnancy, renal failure, or heart failure
Risk factors
- Female gender (women are 3 times more likely than men)
- Age between 40-60 years
- Jobs requiring intensive wrist use (typing, manual crafts)
- Obesity and elevated BMI (BMI > 30)
- Chronic diseases such as diabetes, hypothyroidism, and kidney disease
- Pregnancy and perimenopausal period
- Rheumatologic diseases and arthritis
- Family history of the condition
- Prolonged wrist immobility (such as long-term casting)
- Previous wrist injuries and trauma
Diagnosis
Diagnosis rests on history and physical examination including Tinel's sign (tapping over the tunnel elicits tingling) and Phalen's test (sustained wrist flexion reproduces symptoms within 60 seconds). Electrodiagnostic studies (nerve conduction velocity and EMG) confirm the diagnosis, quantify severity, and guide treatment decisions. Ultrasound imaging can visualize median nerve swelling and identify structural causes.
Treatment
Conservative treatment includes neutral wrist splints worn at night, activity modification, ergonomic adjustments, and intra-canal corticosteroid injections that relieve symptoms for weeks to months. Surgical carpal tunnel release — open or endoscopic — divides the transverse carpal ligament and is the definitive treatment when conservative measures fail or thenar atrophy is present. Most patients report significant improvement within weeks of surgery.
Complications
- Permanent thenar muscle atrophy with loss of thumb opposition if decompression is delayed
- Chronic pain and persistent sensory loss from irreversible nerve damage
- Permanent grip weakness impairing occupational capacity
Prevention
- Ergonomic workplace setup: wrist-neutral keyboard position, padded mouse support
- Regular stretch breaks during repetitive wrist tasks
- Protective splints during high-risk activities or manual labor
- Maintaining healthy weight to reduce fluid retention and systemic risk factors
When to see a doctor
Seek medical evaluation if numbness or pain persists beyond two weeks, if hand weakness interferes with daily activities or work, if you notice thenar muscle wasting, or if symptoms do not improve with nighttime splinting. Early intervention prevents permanent nerve damage and maximizes surgical outcomes.