Carpal tunnel syndrome is compression of the median nerve in a narrow channel at the wrist, causing numbness, tingling and night-time symptoms in the thumb, index and middle fingers [1][3]. For mild to moderate symptoms we start with a night splint and activity changes, with a steroid injection if needed; surgery is considered when symptoms persist, are severe, or there is clear nerve damage such as muscle wasting [1][3].
Why does the nerve get squeezed?
On the palm side of the wrist the bones and a thick ligament above them form a narrow channel. The tendons that bend the fingers and the median nerve pass through it; when the pressure inside rises the nerve is compressed [1][3].
The median nerve supplies feeling to the thumb, index and middle finger and part of the ring finger, which is why symptoms are usually felt there [1][3].
Which symptoms point to it?
Symptoms usually start slowly and can build up over time [1][2][3]:
- Numbness, tingling or burning in the thumb, index and middle fingers
- Symptoms that are worse at night and wake you, easing when you shake the hand
- Pain spreading from the fingers into the hand and up the arm
- Weaker grip, clumsiness, dropping things
- In advanced cases, wasting of the muscles at the base of the thumb
Who is more likely to get it?
For most people there is no single cause. Being born with a narrower channel, repetitive jobs that bend the wrist often and forcefully, and keeping the wrist strongly bent for long periods may raise the risk [1][2]. Pregnancy, excess weight, diabetes, joint diseases such as rheumatoid arthritis, a family history and an earlier wrist injury are also known risk factors [1][2].
How is it diagnosed?
Diagnosis rests largely on your story and examination: we check feeling and muscle strength in the fingers and see whether tapping over the wrist or holding it in certain positions brings on the symptoms [1][3].
Nerve conduction studies and EMG show how much the nerve is affected and help separate it from other nerve problems. Ultrasound, X-ray or MRI are requested in selected patients; these tests are not needed for everyone [1][3].
Non-surgical options first
For mild and moderate symptoms a night splint that keeps the wrist straight, avoiding movements that strain the wrist and short-term painkillers are the first steps [1][2]. According to a Cochrane review the evidence on splinting is limited, but a night splint may give some overall improvement in the short term and serious harm is not expected [5].
If a splint is not enough a steroid injection into the carpal tunnel can be given. It often reduces symptoms, although in some patients the effect is temporary [1][2].
When is surgery discussed?
Surgery comes up if symptoms persist or return despite non-surgical treatment, if they are severe and long-standing, if tests show clear nerve damage or if the muscles at the base of the thumb start to waste [1][3]. Muscle wasting and constant numbness point to a risk of permanent nerve damage and should not be left waiting [1].
The decision is shared and depends on how severe your symptoms are and what you prefer. The Cochrane review notes that people with tolerable symptoms can start with non-surgical treatment and those with severe symptoms can choose surgery [4]. In a large randomised trial, patients who started with surgery were more likely to be improved at 18 months than those who started with a steroid injection [6].
In the operation the ligament pressing on the nerve is cut to widen the channel; it is usually done under local anaesthetic, quickly, as a day case [1][2][3].
After surgery
Night waking settles within the first week for most patients and the hand can be used for light tasks within a few days [1][3]. Returning fully to daily tasks usually takes a few weeks. Grip strength can take several months to return; in long-standing severe compression feeling can keep improving for up to a year and sometimes does not recover fully. Tingling usually improves before strength does [1][2][3].
When not to wait
Do not delay examination if [1][2]:
- Numbness has become constant or feeling loss is increasing
- The muscles at the base of the thumb are wasting or you have clear weakness
- You often drop things or struggle with buttons
- Symptoms are getting worse or not going away despite home measures
Frequently asked questions
- Is carpal tunnel the commonest cause of numb hands?
- If numbness is in the thumb, index and middle fingers and is worse at night, it is the commonest cause. Other nerve problems can give similar symptoms, so examination and, if needed, a nerve conduction test matter [1][2].
- Does it go away by itself?
- Mild symptoms can ease by avoiding wrist-straining movements and wearing a night splint. If they are not settling, are getting worse or weakness starts, see a doctor [2][5].
- Do I need an EMG?
- Not for everyone. Diagnosis is usually made by examination; nerve conduction studies are requested if the diagnosis is unclear, if we want to see how severe the compression is or when surgery is planned [1][3].
At our clinic we decide with you, looking at how much the symptoms disturb your sleep and work and at the feeling and strength in your fingers.
Sources
- Carpal Tunnel Syndrome. American Academy of Orthopaedic Surgeons (OrthoInfo), n.d.. orthoinfo.org
- Carpal tunnel syndrome. NHS (nhs.uk), 2024. nhs.uk
- Carpal Tunnel Syndrome. British Society for Surgery of the Hand (BSSH), n.d.. bssh.ac.uk
- Surgical versus non-surgical treatment for carpal tunnel syndrome (Cochrane Review). Cochrane Database of Systematic Reviews (Lusa V, et al.), 2024. pubmed.ncbi.nlm.nih.gov
- Splinting for carpal tunnel syndrome (Cochrane Review). Cochrane Database of Systematic Reviews (Karjalainen TV, et al.), 2023. pubmed.ncbi.nlm.nih.gov
- Surgery versus corticosteroid injection for carpal tunnel syndrome (DISTRICTS): an open-label, multicentre, randomised controlled trial. The Lancet (Palmbergen WAC, et al.), 2025. pubmed.ncbi.nlm.nih.gov
This article is general information and does not replace an examination or imaging. If you have symptoms, see a doctor.
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- Numbness and tingling in the hand and fingers: causes, what helps, who to see
- Cut tendons and nerves in the hand: when is it urgent?
- Trigger finger: injection or surgery?