Introduction
Carpal tunnel syndrome is a common cause of pain and numbness in the hands. In this condition the median nerve, one of the main nerves supplying the hand, is compressed. This compression happens as the nerve passes through a tight space in the wrist – the carpal tunnel.
Causes
Anything that increases pressure within the carpal tunnel can give rise to carpal tunnel syndrome. While there is usually no specific cause identified, there are some conditions, such as pregnancy, diabetes and thyroid disorders, which can make carpal tunnel syndrome more likely. Occupational causes – like awkward hand positioning, or use of vibrating tools, can also be a contributing cause.
Symptoms
Dysfunction of the median nerve in carpal tunnel syndrome can cause tingling and numbness in the fingers and occasionally weakness of the muscles at the base of the thumb. This is often worse at night or when there is pressure on the palm such as when driving or riding a bike.
Tests
Often a diagnosis of carpal tunnel syndrome will be made after clinical examination, but in some cases nerve conduction studies or imaging with ultrasound or MRI scans may be required to confirm the diagnosis.