Carpal tunnel syndrome is caused by increased pressure on the median nerve as it passes through the carpal tunnel in the wrist. The median nerve gives feeling to the thumb, index, middle, and ring fingers, and powers the small muscles at the base of the thumb. Increased pressure on the nerve can be caused by repetitive hand movements, fluid retention (e.g. during pregnancy), wrist injuries, inflammatory and non-inflammatory arthritis (e.g. rheumatoid and osteoarthritis), among other factors. In many cases no specific cause is identified.

Symptoms include tingling, and pain in the thumb, index, middle, and part of the ring finger. Over time, this may progress to persistent numbness. Weakness in the hand, particularly for movements of the thumb such as picking up small items, or doing up buttons, may occur. Symptoms are often worse at night or first thing in the morning.

Diagnosis is typically based on the history of symptoms and physical examination. Clinical tests (specific hand movements and positions which your doctor will ask you to do as part of a clinical examination) are used. Many patients with carpal tunnel syndrome will also have another condition that causes symptoms in their hands (for example arthritis), and your doctor will check for this. Nerve conduction studies are sometimes appropriate, and can confirm the diagnosis and assess the severity of median nerve compression.

Yes. Mild to moderate carpal tunnel syndrome can often be managed with wrist splints (worn particularly at night), corticosteroid injections, and activity modification. These measures can provide significant relief, though symptoms may recur over time. Surgery offers a more definitive solution for persistent or severe cases.

Carpal tunnel release is a relatively quick procedure, typically taking approximately 15–30 minutes. It is usually performed under local anaesthetic as a day case.

Most patients can return to light activities within a few days and to office work within 1–2 weeks. Full recovery, including return to heavy manual work, typically takes 4–6 weeks. Most patients will experience close to immediate relief from tingling/pins and needles. If persistent numbness has been present prior to surgery, it may not fully resolve following surgery. Any weakness of the thumb muscles may not fully resolve, but should not progress further.

Carpal tunnel release is a safe procedure with a high success rate. Risks include infection, bleeding, scarring, incomplete relief of symptoms, recurrence, and rarely, injury to surrounding nerves or tendons. About 1 in 10 patients will experience an achy sensation known as "pillar pain" in the heel of the hand following surgery, and about 1 in 100 patients will find that this ache/discomfort persists. Complex regional pain syndrome is an uncommon complication, which can give rise to persistent pain in the treated hand. In some patients, the scar can go through a period of hypersensitivity: attending hand therapy and adhering to the scar management advice you are given is effective for the great majority of patients who experience this. In patients who have carpal tunnel syndrome in both hands, it is common for the symptoms in the hand which has not been operated on to seem to get worse in the first few weeks following surgery. If there is another condition causing pain in the hand and impacting grip strength (commonly osteoarthritis), symptoms from that condition are not relieved by having this operation done. Your surgeon will discuss all risks at consultation.