Carpal Tunnel Syndrome: Causes, Symptoms, Diagnosis, and Treatment
Carpal tunnel syndrome (CTS) is one of the most common nerve compression disorders, occurring when the median nerve — which runs through the wrist's carpal tunnel — is compressed. It affects people who perform repetitive hand and wrist movements, and is more common in certain occupations, during pregnancy, and in people with conditions such as diabetes, thyroid disorders, or arthritis.
Symptoms
- Numbness, tingling, or a "pins and needles" sensation in the thumb, index, and middle fingers (the median nerve distribution).
- Pain or burning sensation in the hand and wrist, sometimes radiating up the forearm.
- Weakness in the hand and a tendency to drop objects, in more advanced cases.
- Symptoms are often worse at night and may wake you from sleep; shaking the hand (the "flick sign") often relieves them temporarily.
Causes and risk factors
The carpal tunnel is a narrow passageway of bone and ligament at the base of the hand. Anything that narrows this tunnel or enlarges the tissues within it can compress the median nerve: repetitive hand/wrist movements, prolonged wrist positions (flexion or extension), wrist injuries, pregnancy-related fluid retention, obesity, diabetes, and inflammatory conditions.
Diagnosis
Diagnosis is based on symptoms and a physical exam (including Tinel's sign and Phalen's test), and can be confirmed with nerve conduction studies (electromyography/nerve conduction velocity) that measure how well the median nerve conducts signals. Ultrasound can also visualize the nerve and tunnel.
Treatment
- Conservative first: wrist splinting (especially at night), activity modification, ergonomic adjustments, and nonsteroidal anti-inflammatory drugs.
- Injections: corticosteroid injections into the carpal tunnel can provide temporary relief.
- Surgery: carpal tunnel release — open or endoscopic — is considered when conservative treatment fails or nerve damage is severe/progressive. It is highly effective in most cases.
- Underlying conditions: treating contributing conditions (e.g., optimizing diabetes or thyroid control) is part of the plan.
Early recognition and treatment improve outcomes — prolonged compression can lead to permanent nerve damage and muscle wasting at the base of the thumb. This article is for general educational purposes and is not a substitute for individualized medical advice; see a doctor for proper diagnosis.
Helpful products
- Wrist brace / night splint — the standard first-line conservative tool for carpal tunnel symptoms.
Source: National Institute of Neurological Disorders and Stroke (NINDS)
