Carpal tunnel syndrome occurs when a combination of health conditions and activities puts pressure on the median nerve as it passes through the carpal tunnel in your wrist. This pressure leads to symptoms. Anything that decreases the amount of space in the carpal tunnel, increases the amount of tissue in the tunnel, or increases the sensitivity of the median nerve can lead to carpal tunnel syndrome.
Things that help cause carpal tunnel syndrome include:
- Conditions or illnesses that can cause or contribute to arm pain or swelling in the joints and soft tissues in the arm, or to reduced blood flow to the hands. These include obesity, rheumatoid arthritis, gout, diabetes, lupus, and hypothyroidism.
- Repeated hand and wrist movements. They can cause the membranes surrounding the tendons to swell (tenosynovitis).
- Broken wrist bones, dislocated bones, new bone growth from healing bones, or bone spurs. These can take up space in the carpal tunnel and put more pressure on the median nerve.
Carpal tunnel syndrome is a common work-related condition. It can be caused by work that requires:
- Forceful or repetitive hand movements.
- Hand-arm vibration.
- Working for long periods in the same or awkward positions.
Carpal tunnel syndrome is even more likely if you have these work-related issues along with other health conditions.
In some cases the cause of carpal tunnel syndrome cannot be found.