What Is Carpal Tunnel Syndrome

What Is Carpal Tunnel Syndrome (With Anatomy and Symptoms Description)

Carpal Tunnel Syndrome

The human body’s nervous system is complex and each of the nerves has a specific role to play in the proper functioning of our bodies. In this article, we’ll dedicate our attention to the median nerve. 

Namely, this nerve starts from the neck and travels down your arms, all the way to your wrists. On its way to your fingers, it traverses through the carpal tunnel. The “trouble” is that, it can get compressed or pressed in the tunnel, resulting in numbness, loss of functions, and “tingling.”

There are several stages of syndrome progression. Depending on the stage and severity of the condition, people might recognize symptoms like weak grip, extreme clumsiness, and sharp pain. People typically dismiss this as a mere cramp, but there’s a good reason why the medical term involves the word “syndrome.” While it is not as severe as other conditions it can still progress to cause damage and injuries to the entire hand.

When the median nerve that originates in the neck travels through the so-called carpal tunnel, it can be pressed or even compressed due to outside pressure or overextending of the wrist. All this can cause carpal tunnel syndrome (or short, CTS) and further develop unpleasantness and even serious injuries that can end up requiring plastic surgery. 

Wrist and Hand Anatomy

The nerve we’re referring to is the median nerve. Namely, it’s the nerve which is directly responsible for the sensation in our fingers. The fact that it’s located in the same place in both animals and humans gives merit to Darvin’s theory. 

More specifically, there are a total of five main nerves coming from the brachial plexus which is located in the neck. The median nerve goes through the inner part of the arm and eventually goes through the carpal tunnel. It is also the only nerve going through the carpal tunnel. 

If we observe the transection of the wrist, we can see that beside carpal bones, there are only muscles and tendons controlling the flexing of the thumb and fingers. The carpal tunnel is set between four carpal bones and the transverse carpal ligament. The tunnel is approximately an inch wide, and there is only the median nerve beside tendons passing through. Nine tendons that go through this tunnel are controlling both flexing and the movement of all fingers except the pinky. The tendons are also called flexor tendons.

Wrist and Hand Anatomy

Since the roof of the tunnel, located on the inner side of the wrist or, more precisely, palm side, is a strong band of connecting tissue (or transverse carpal ligament), it has little to no ability to stretch or change its size in any way. 

As we’ve already mentioned, the median nerve is the only nerve in the tunnel, and it is one of the main nerves in the hand. Furthermore, it provides a sense of touch in the thumb, index finger, middle, and the ring finger. 

Carpal Tunnel Syndrome

CTS occurs when the median nerve is compressed, when the tunnel becomes narrow, or even when the tissue surrounding the flexor tendons swells. As a result, this will put direct pressure on the median nerve that will cause the syndrome. Furthermore, any activity or situation that causes the median nerve to be pressured might cause CTS. The tissue around the tendons is called synovium. 

The other causes of the syndrome can be both intrinsic and extrinsic, which means that they can originate both inside and outside the tunnel. 

Interestingly, the median nerve can move almost 10 millimeters to allow wrist flexing. Long-term compression of this nerve can cause damage and scarring which can lead to the nerve adhering to the tissue around it and causing it to stay in a locked position, which will reduce the movement of the wrist. Finally, constant repetitive motion can cause swelling of the tissue that might lead to CTS. However, while there are endless talks about keyboard and CTS, there is no correlation between using a computer and carpal tunnel.

While constant use of a keyboard can hurt the wrist and cause unpleasantness and pain, CTS is not the thing that is related to keyboards and typing. 

If CTS progresses, it can cause a tingling sensation or numbness in the thumb, index, and middle fingers. Furthermore, it can cause a feeling of shock until it becomes almost constant. Finally, it will result in a noticeably weaker grip and general weakness in the hand. 

Symptoms and Diagnostics

The most common symptoms of CTS are numbness, pain in both the wrist and fingers (the pain can even go to the forearm or the upper arm), and tingling. The symptoms can be felt in the thumb, index, middle, and even on the thumb side of the ring finger. While symptoms usually occur during the night, if untreated, it will expand to constant pain and numbness. Furthermore, the pain may also progress to the rest of the arm if the syndrome remains untreated. 

Diagnosing CTS is rather simple. Doctors will use a combination of your history as well as a physical examination, and even nerve tests that can determine whether there is any nerve damage. These tests are also called nerve conduction studies. 

Finally, there is a case of advanced CTS where muscles in the base of the thumb waste away or atrophy.


  • Numbness in fingers and half of the hand. Sometimes even a burning sensation or tingling
  • Shocking sensation from time to time (similar to electric shock)
  • Hand weakness and clumsiness 
  • Losing proprioception (general idea where your hand is)
  • Pain in the wrist that can transfer to the rest of the hand
  • Discomfort

Risks Factors and Statistics

When it comes to CTS, there are several risk factors that might cause this symptom. Among them are constant and repetitive wrist work, obesity, genetics, pregnancy, and rheumatoid arthritis. 

Furthermore, women are three times more likely to suffer from this condition. The majority of CTS causes are still unknown. 

Prevention and Treatment 

One of the main ways to decrease the risk of CTS is being physically active. Furthermore, wearing a wrist splint can alleviate the symptoms as well as using corticosteroids. Finally, surgery with cutting the ligament (carpal transverse ligament) shows better and more effective results compared to the treatments without surgeries. 

There is little to no information and data that support the use of a wrist rest or any other prevention method. Because of the use of the hand and multiple other factors, it is difficult to find and determine the leading cause of CTS. Besides, reducing the constant pressure on your wrist, as well as overextending, might help you in the long term. 

Usually, the treatment for CTS will be based on physical therapy, with or without additional steroids. Naturally, if the syndrome is in its late stages, there will be a need for surgery like carpal tunnel release. Carpal tunnel release is a surgery with the goal of releasing the carpal ligament.

Most of the patients after the treatment or surgery find minimal residual or nerve damage. However, elderly people with longer exposure might suffer from permanent nerve damage, like irreversible numbness, for example. Finally, the patients that had carpal ligament surgery are more likely to develop the so-called trigger thumb after the surgery. 

SplintersInjectionsPhysical TherapySurgery
BracesCorticosteroidsNerve gliding exercisesOpen carpal tunnel release
SplintsNon-steroid anti-inflammatory drugsChanging habits(Lifestyle change)Endoscopic carpal tunnel release
Immobilization during the night CortisoneYoga

Treating any other condition you might haveAvoid overextending wrist

Final Words

It is still uncertain what can cause CTS. However, even though there are some unanswered questions, early treatment is still the best option. If you feel repetitive or constant numbness or if you feel weakness in your grip or wrist, it might be a good idea to visit your physician or doctor to make sure that everything is ok. It is always a better option to detect CTS in an early phase when it can be fixed with wrist braces and splints.