Carpal Tunnel Syndrome
Pressure on the median nerve where it passes through a narrow tunnel at the wrist, which can cause numbness, tingling and weakness in the hand.
The carpal tunnel is a narrow passage on the palm side of the wrist. Its floor and walls are formed by the small wrist bones, and its roof is a thick band of tissue called the transverse carpal ligament. Nine tendons that bend the fingers and thumb run through this tunnel - and so does the median nerve.
When pressure inside the tunnel rises, the median nerve is the structure that suffers first. Nerves are sensitive to pressure: they need a steady blood supply to work, and sustained compression interferes with it. The result is the familiar pattern of numbness and tingling in the thumb, index, middle and half of the ring finger.
Carpal tunnel syndrome is common, and for many people it is manageable without surgery - particularly when it is recognised early.
Loading anatomy
Common symptoms
- Numbness or tingling in the thumb, index, middle and part of the ring finger
- Symptoms that wake you at night, or that are worst first thing in the morning
- Tingling when driving, holding a phone or reading a book - anything that holds the wrist still
- A feeling that the hand is swollen or clumsy, even when it looks normal
- Dropping small objects, or difficulty with buttons, keys and jar lids
- In longer-standing cases, weakness or visible thinning of the muscle at the base of the thumb
Causes and contributing factors
- Anything that reduces the space inside the tunnel or increases the volume of its contents
- Swelling or thickening of the tendon linings that share the tunnel with the nerve
- Wrist fractures or dislocations that change the shape of the tunnel
- Pregnancy, thyroid disease, diabetes, inflammatory arthritis and other medical conditions
- Sustained or repetitive hand use may contribute to symptoms in some people, though the relationship is not simple and is often over-stated
If you have already had surgery for this
Continued or returning symptoms after a previous carpal tunnel release is one of the more common reasons people seek a second opinion.
How it is evaluated
Evaluation begins with the story: which fingers, at what time of day, what makes it better or worse, and what you can no longer do comfortably. That history is often more informative than any single test.
A physical examination follows - checking sensation in specific nerve territories, the strength of the thumb muscles, and how symptoms respond to particular wrist positions or gentle pressure over the nerve.
- A detailed history of symptoms, timing and hand function
- Examination of sensation, thumb strength and muscle bulk
- Assessment of the neck, elbow and forearm, because nerve symptoms can originate above the wrist
- Nerve conduction studies and electromyography in selected cases, to measure how well the nerve is conducting signals
- Imaging where a fracture, mass or other structural problem is suspected
Clinical detail
Electrodiagnostic testing is used to support the clinical picture rather than replace it. Studies can be normal early in the disease and are interpreted alongside examination findings.
Differential considerations include cervical radiculopathy, proximal median nerve compression, generalised peripheral neuropathy and, less commonly, a double-crush pattern in which compression exists at more than one level along the nerve.
Nonsurgical treatment
Many people improve without an operation, especially when symptoms come and go rather than being constant.
The aim of nonsurgical care is to reduce pressure on the nerve and give it a chance to recover.
- A wrist splint worn at night, which keeps the wrist from bending into positions that raise pressure in the tunnel
- Changes to how a task is performed, or how long it is performed for
- Treatment of contributing medical conditions
- A corticosteroid injection into the carpal tunnel, which can reduce swelling and often helps temporarily - the response can also provide useful information
- Hand therapy, including nerve and tendon gliding exercises
Surgical treatment
When symptoms persist despite nonsurgical care, or when there is evidence that the nerve is being damaged - constant numbness, or weakness and wasting of the thumb muscles - surgery is usually discussed.
The operation is called carpal tunnel release. The transverse carpal ligament, the roof of the tunnel, is divided. This enlarges the tunnel and lowers the pressure on the median nerve. The ligament is not removed and the tendons are not disturbed.
Recovery of sensation depends on how long the nerve has been compressed and how much it has been affected. Nerves recover slowly, and some people with long-standing compression have residual numbness. This is discussed honestly before any operation.
- Carpal tunnel release, performed through an open or endoscopic approach depending on the individual situation
- Most often performed as a day procedure
- Anaesthetic options vary and are discussed individually
Clinical detail
Open and endoscopic release have both been studied extensively. Reported long-term outcomes are broadly similar; the differences lie mainly in the early recovery period and in the specific anatomy of the individual patient.
In patients with previous wrist surgery, previous carpal tunnel release, distorted anatomy or an atypical symptom pattern, the operative approach and the plan for exposure require additional consideration.
Recovery
Night-time symptoms often settle quickly after a successful release - sometimes within days. Numbness present all day, and any weakness, generally improves more slowly, over months, as the nerve recovers.
Tenderness in the palm around the incision is common for a period after surgery and gradually improves. Hand therapy is used where it is helpful.
- Light use of the hand is usually encouraged early, guided by your surgeon
- Grip strength typically takes several weeks to months to return
- Return to work depends on the demands of the job and is planned individually
When to seek urgent care
Seek immediate medical attention - an emergency department - if you experience:
- Sudden, severe numbness or loss of hand function after an injury
- Rapidly worsening weakness in the hand
- Numbness accompanied by severe pain, swelling or a pale, cold hand
- Signs of infection after any surgery - spreading redness, fever, increasing pain or wound drainage
This list is not exhaustive. If something about your hand worries you, have it looked at.
Frequently asked questions
Does carpal tunnel syndrome always need surgery?
No. Many people improve with splinting, activity changes, treatment of contributing medical conditions, or an injection. Surgery is generally considered when symptoms persist despite these measures, or when there are signs that the nerve is being damaged.
Will the numbness definitely go away after surgery?
Carpal tunnel release reliably removes the pressure on the nerve, but how much sensation returns depends on how long and how severely the nerve was compressed. People treated early tend to recover more completely. Long-standing compression can leave some permanent numbness, and this is discussed before surgery rather than after.
I had carpal tunnel surgery and I am still numb. What does that mean?
There are several possible explanations, and they are not all the same. The nerve may still be recovering. The compression may not have been fully relieved. Symptoms may be arising from another level along the nerve, or from a different problem altogether. Persistent symptoms after surgery deserve a careful reassessment rather than an assumption.
Is typing responsible for carpal tunnel syndrome?
The link between ordinary computer use and carpal tunnel syndrome is weaker than commonly believed. Forceful, repetitive or vibrating hand work has a clearer association. Many people develop it with no obvious occupational cause at all.
Related conditions
Peripheral Nerve Injuries
Damage to the nerves that carry signals between the brain and the hand, causing numbness, weakness or pain in the territory that nerve supplies.
Tendon Injuries
Cuts, ruptures or damage to the cords that connect muscle to bone and make the fingers and thumb move.
Wrist Fractures
Breaks involving the end of the forearm bones or the small bones of the wrist, most often after a fall onto an outstretched hand.
Discuss carpal tunnel with Dr. Champagne
A consultation begins with understanding your symptoms, how they affect what you do, and what has already been tried.