Carpal Tunnel Syndrome (CTS)


The carpal tunnel is a narrow structure formed by the wrist (carpal) bones. The top of the tunnel is formed by connective tissue (transverse carpal ligament). The medial nerve passes through this tunnel, and it controls feeling in the fingers, thumb, and palm. Also going through the tunnel are the flexor tendons, which bend the fingers and thumb.

With carpal tunnel syndrome (CTS), the tissues around the flexor tendons swell, putting pressure on the median nerve. Swelling of the synovium (tissue that lubricates the tendons) narrows the carpal tunnel and further compress the median nerve.

Risk Factors for CTS

The Centers for Disease Control and Prevention (CDC) reports that an estimated 3% of employed adults have carpal tunnel syndrome, and women are more likely to report this condition than men. Several factors contribute to the development of carpal tunnel syndrome. These include:

  • Heredity – Some people have smaller carpal tunnels than others, and this trait tends to be hereditary.
  • Age – CTS occurs more frequently in older people.
  • Hormones – Changes in hormones can contribute to the development of CTS.
  • Medical conditions – CTS is seen in people with diabetes, thyroid disease, and rheumatoid arthritis.
  • Overuse – Doing a job that involves repetitive use of the wrist contributes to this condition.

Symptoms of CTS

The symptoms of CTS come on gradually, and they are not related to an injury. Many carpal tunnel anatomy picturepeople complain of symptoms worse at night, because the wrist curls up during sleep. These symptoms usually come and go, and occur worse with certain activities. This includes using the phone, lifting objects, reading, and/or driving. Symptoms include:

  • Tingling, numbness, and pain in the fingers and hand
  • Strange and foreign sensations and pain, which travel up the arm to the shoulder
  • An electric shock feeling in the thumb and fingers
  • Weakness or clumsiness when performing certain activities

Diagnosing Carpal Tunnel Syndrome

The doctor will take a medical history and conduct a physical examination. In addition, he/she will examine the hand using physical and diagnostic tests, such as:

  • Tapping along the median nerve (assess for tingling in the fingers)
  • Pressing down on the median nerve (look for numbness and tingling)
  • Assessing for weakness of the muscles below the thumb
  • Conducting an electrophysiological nerve test
  • Taking x-rays of the wrist and hand

CTS Treatment

Carpal tunnel syndrome can be treated without surgery, in some cases. Based on the doctor’s findings, treatment options include:

  • Brace/splint – An immobilizing device is often used to keep the wrist in a neutral position. This prevents further compression of the median nerve.Carpal tunnel wrist bracing
  • Medications – The doctor may recommend nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen.
  • Corticosteroid injections – To provide long-lasting relief, the doctor may inject a steroid near the median nerve or into the carpal tunnel to decrease inflammation and swelling. In a recent observational study, researchers found that the 3-month follow-up success rate was 77% with these injections. In addition, patients had a 63% success rate at 6 months, and almost a 50% success rate at 12 months.
  • Carpal tunnel release surgery – Either open or endoscopic surgery can be done to sever the band of tissue around the wrist and reduce the pressure. The open procedure involves a 2-inch incision in the wrist, whereas the endoscopic technique involves two small ½ inch incisions.


Center for Disease Control and Prevention (2010). Quick Stats. Retrieved from:

Lalonde DH (2014). Evidence-based medicine: carpal tunnel syndrome. Plastic Reconstructive Surgery, 133(5), 1234-1240. DOI: 10.1097/PRS.0000000000000092.