Why Is Carpal Tunnel So Common?

According to the literature, carpal Tunnel Syndrome (CTS) is one of the most prevalent upper extremity complaints. In fact, it IS the most common “compression neuropathy” (of which there are many) and affects 3-6% of adults in the general population. Additionally, CTS can affect BOTH hands in up to 50% of patients with the condition!

The CAUSE of CTS is often unknown and typically comes on gradually, making it difficult to determine a definite cause or specific “date of onset” for CTS.

Symptoms such as numbness, tingling, loss of dexterity, loss of strength (like pinch or grip), and the need to shake the hand or flick the fingers to restore sensation are ALL VERY COMMON CTS SYMPTOMS. The REASON for these symptoms boils down to one thing: The median nerve in the wrist gets pinched! The cause/s can include:

1)  Repetitive motion from either work or hobbies like assembly line work or playing a musical instrument can cause swelling within the carpal tunnel, placing extra pressure on the median nerve as it passes through.

2)  Obesity can contribute to CTS due to extra fluids or fatty deposits that can build up within the carpal tunnel.

3)  Pregnancy: Elevated levels of the hormones estrogen and progesterone can cause the body to retain fluids and increase pressure in the carpal tunnel.

4) Arthritis: Osteoarthritis can lead to CTS (such as when a spur forms inside the tunnel). Rheumatoid arthritis can lead to an autoimmune response and antibodies that end up attacking the cartilage of the joints in the wrist, which can lead to CTS.

5)  Hormone-related conditions: In diabetes mellitus, the blood becomes thicker due to high sugar levels (like syrup) and can’t pass through the small blood vessels, resulting in “neuropathy,” which can make CTS more likely. In hypothyroid, low thyroid function results in “myxedema,” a specific type of swelling that makes CTS more likely to occur.

6)  Trauma: A wrist fracture could cause the carpal tunnel to “collapse” or change in shape resulting in less space for the nerve to travel through.

7)  Mass lesions: A “ganglionic cyst” is a good example. This is where joint fluid leaks out and forms a “bump” on the INSIDE the carpal tunnel, which reduces space and increases pressure in this anatomical structure.

8)  Amyloidosis: This is a rare condition where a protein substance called “amyloid” builds up in any tissue or organ. If this occurs in the wrist, it can “pinch” the median nerve as it passes through.

9)  Sarcoidosis: This is the growth of small collections of inflammatory cells called “granulomas,” which can accumulate in different parts of the body. If it occurs in the wrist, pinching can occur.

10)  Multiple Myeloma: This is a type of cancer that affects the bone marrow, and inflammation in the wrist can occur creating the pressure increase on the median nerve that can lead to CTS.

11)  Leukemia: This too is a type of cancer that involves the white blood cells, and CTS can result from its effects on the tissues in the wrist.

12)  Anatomy: The size and shape of the carpal tunnel is hereditary, and some of us have a smaller tunnel than others. If CTS is present in multiple family members, this “genetic” factor may play a role.

There are other conditions that can “mimic” CTS, but doctors of chiropractic are trained to perform an accurate history and examination so treatment can be directed in the proper manner!