What is Carpal Tunnel Syndrome (CTS)?

11 Nov 2018



Carpal tunnel syndrome (CTS) is a commonly diagnosed condition but can be poorly understood. Around 2.7% of people will get carpal tunnel syndrome in their lives. You’ve probably heard of carpal tunnel syndrome, but how much do you actually know about it? 


In this blog we will explore the anatomy of the wrist, forearm and hand, the symptoms of carpal tunnel syndrome, the causes and what you can do to resolve this, generally without surgery. 


The anatomy 




The carpal tunnel is a narrow passageway on the palm side of the wrist that allows the median nerve and 9 tendons to pass through it, from the forearm and into the hand and fingers. The transverse carpal ligament creates the roof of the carpal tunnel and the wrist bones (carpals) create the walls and floor (see image).


The 9 flexor tendons include the flexor pollicis longus (flexes the thumb), 4 flexor digitorum profundis and 4 flexors pollicis superficialis (flex the 4 fingers). These tendons originate from the muscles that all originate from the inside of the elbow. 

The median nerve runs from the brachial plexus in the neck and travels under the collarbone, through the armpit, to the elbow and then down the middle of the forearm to the fingers, via the carpal tunnel. 




The symptoms are the most important part of the diagnosis of carpal tunnel syndrome. These symptoms include:


  • Tingling or numbness in the thumb, index finger, middle finger and half of the ring finger (the half closet to the middle finger) on the palm side of the hand (see the picture) and the palm. On the back side of the hand it is more the tips of the thumb, index, middle and half of the ring finger that is affected. The rest of the back of the hand and those fingers is innervated by the radial nerve. The ulnar nerve controls the rest of the ring and pinky fingers as well as the pinky side of the hand. 


  • Weakness in the fingers that are innervated by the median nerve. This can manifest by dropping objects.

  • Aching or pain in these fingers, the palm and/or the wrist. 




This is where is gets tricky as there are many opinions and outdated information as to how carpal tunnel is caused. 

  • Hereditary. 50% of people have CTS where it has been passed on from the parents and determined in the genes.

  • Overuse. People who do repetitive tasks for work using their fingers and hands, such as process factory workers, cleaners, people doing data entry and just computer work in general are found to suffer the most.

  • Pressure on the wrist. If you use a computer and rest your wrists on the table or laptop then you will be compressing the carpal tunnel. Over time this may form adhesions between the transverse carpal ligament and the median nerve. This can then cause the carpal tunnel syndrome symptoms. You can try getting a gel wrist rest, taking breaks, stretching and adjusting your desk setup to avoid pressure on the wrists.

  • Diabetes. Diabetes, especially type 1 (genetic and not lifestyle based like type 2) can lead to nerve damage amongst other things. If you have diabetes then you are at a much higher risk of CTS.

  • Other neurological conditions that affect nerves such as multiple