What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) is pressure on the median nerve as it passes through the carpal tunnel, a narrow passage formed by the wrist bones and the transverse carpal ligament. Because the median nerve supplies feeling to the thumb, index finger, middle finger and the thumb side of the ring finger, those fingers go numb or tingle. A Swedish population study (Atroshi et al., 1999) found clinically confirmed CTS in about 3.8% of adults.
Causes and risk factors
- Repetitive or forceful hand use, especially with a bent wrist or vibrating tools
- Hormonal and metabolic factors: pregnancy, hypothyroidism, diabetes, obesity
- Structural changes: wrist fractures, arthritis, swelling of the tendon sheaths
- Sex and age: more common in women and in people aged 40–60
The link with computer use is mixed in the research, so typing alone is not considered a proven cause.
Symptoms and diagnosis
Early on, many people wake up at night with numb hands and "shake it out" for relief. Over time, fine tasks like buttoning a shirt get harder, and the muscles at the base of the thumb can waste away. Doctors check Phalen's test (holding the wrist flexed for about a minute; Phalen, 1966) and Tinel's sign (tapping over the nerve), then confirm and grade severity with nerve conduction studies/EMG or ultrasound.
Treatment
Mild cases often improve with a night splint that keeps the wrist straight, changes to work habits, and corticosteroid injections. If numbness is constant or the thumb muscles weaken, carpal tunnel release surgery, which cuts the transverse carpal ligament, is considered (Padua et al., 2016). Long-standing nerve damage recovers slowly, so weakness is a reason to get checked sooner rather than later.
Prevention at the desk
Set your keyboard and mouse so your wrists stay neutral, and take short breaks every 30–60 minutes. Long phone sessions also strain the neck, so CTS often shows up alongside forward head posture ("tech neck") and computer vision syndrome.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Does hand numbness always mean carpal tunnel?
- No. A pinched nerve in the neck, peripheral neuropathy and diabetes can also cause it. Numbness in the little finger points to a different nerve.
- Can it come back after surgery?
- Most people improve, but symptoms can recur or feeling may not fully return in some cases.
Sources reviewed: 2026-10-25
See also: De Quervain's Tenosynovitis
References
- Phalen, G. S. (1966). The carpal-tunnel syndrome: Seventeen years' experience in diagnosis and treatment of six hundred fifty-four hands. Journal of Bone and Joint Surgery (American Volume), 48(2), 211–228.
- Atroshi, I., Gummesson, C., Johnsson, R., Ornstein, E., Ranstam, J., & Rosén, I. (1999). Prevalence of carpal tunnel syndrome in a general population. JAMA, 282(2), 153–158.
- Padua, L., Coraci, D., Erra, C., Pazzaglia, C., Paolasso, I., Loreti, C., Caliandro, P., & Hobson-Webb, L. D. (2016). Carpal tunnel syndrome: Clinical features, diagnosis, and management. The Lancet Neurology, 15(12), 1273–1284.