In short
Carpal tunnel syndrome is compression of the median nerve at the wrist. A night splint helps mild and recent cases, a steroid injection buys months and sometimes resolves it, and surgery is the only durable answer for severe or long-standing compression. The deciding factors are duration, severity and whether there is already weakness.
The median nerve passes into the hand through a tunnel at the wrist, roofed by a tough ligament. The space is fixed. Anything that reduces it — swelling of the tendon linings, fluid retention, thickening of the ligament — presses on the nerve.
The result is a very characteristic set of symptoms, and recognising them matters, because the condition is treatable and because leaving severe compression too long causes permanent change.
How it presents
Night-time numbness and tingling in the thumb, index, middle and half the ring finger, which wakes people and is relieved by shaking the hand or hanging it over the side of the bed. This flick of the wrist is so typical it has a name in clinical teaching.
As it progresses, symptoms appear in the day — holding a phone to the ear, riding a two-wheeler, reading a newspaper. Later still come dropping things, difficulty with buttons, and visible wasting of the muscle at the base of the thumb.
The little finger is spared, because it is supplied by a different nerve. Numbness that includes the little finger points elsewhere — often the ulnar nerve at the elbow, or the neck.
Why a rheumatologist sees this
Carpal tunnel syndrome is frequently a symptom of something else, and the something else is often in rheumatology's territory:
- Hypothyroidism, which is extremely common and easily tested — see thyroid trouble and aching joints
- Rheumatoid arthritis, where inflamed tendon linings crowd the tunnel
- Diabetes
- Pregnancy, where fluid retention causes it and it usually resolves after delivery
- Obesity, and occasionally acromegaly or amyloidosis
If both hands are affected, or there are other joint symptoms, looking for a cause is worth more than treating the wrist in isolation. A thyroid test and a blood sugar are reasonable first steps in almost everyone.
Choosing the treatment
Night splints hold the wrist straight while you sleep, which is when symptoms are worst — the wrist naturally curls, narrowing the tunnel further. They work best for mild, recent symptoms, cost little, and are worth a proper trial of six to eight weeks. Worn at night, not during the day, unless specifically advised.
Steroid injection into the carpal tunnel reduces swelling around the nerve. It relieves symptoms in most people, often substantially, and that relief typically lasts months rather than forever. It has two roles: treating someone who is likely to improve anyway — in pregnancy, or while a thyroid problem is corrected — and confirming the diagnosis when it is uncertain, since a good response is informative.
Surgery — carpal tunnel release — divides the ligament forming the roof of the tunnel, giving the nerve permanent extra room. It is a short day-case procedure under local anaesthetic, and it is the most reliable treatment for severe or long-standing disease. Recovery of night symptoms is often immediate; recovery of numbness and strength takes longer and may be incomplete if the nerve has been compressed for a long time.
When not to wait
The decision stops being about preference when any of these appear:
- Constant numbness rather than intermittent — the nerve is being compressed continuously
- Visible wasting of the fleshy pad at the base of the thumb
- Weakness of thumb movement, particularly lifting the thumb away from the palm
- Nerve conduction studies showing severe compression
These indicate that nerve fibres are being lost. Splints and injections do not reverse that, and recovery after surgery is less complete the longer it has been present. This is the main reason to get a hand with constant numbness assessed rather than persevering with a wrist support.
Nerve conduction studies
These measure how well the nerve conducts across the wrist. They are useful for confirming the diagnosis when it is unclear, for grading severity, and before surgery.
They are not always necessary. A classic history with classic findings in someone who is going to try a splint first does not need a test to begin treatment. They are most useful when the picture is atypical, when the neck is a possible source, or when surgery is being planned.
A normal study does not completely exclude the diagnosis in early cases, which is worth knowing if your symptoms are typical and the report is normal — much like joint pain with normal blood tests.
What about exercises
Nerve gliding and tendon gliding exercises are often given, and they are reasonable to try alongside a splint in mild cases. The evidence that they change the course is modest. They are not a substitute for treatment when there is constant numbness or weakness.
What does help, practically: adjusting how you hold tools and devices, breaking up long periods of sustained wrist flexion or extension, and dealing with the underlying cause if there is one.
What recovery after surgery looks like
People are often more worried about the operation than the condition, usually because nobody has described what follows.
Carpal tunnel release is a short day-case procedure, generally under local anaesthetic, through a small incision in the palm. You go home the same day with the hand bandaged.
Night symptoms often go immediately — many people report their first undisturbed night straight after surgery. Numbness takes longer, recovering over weeks to months as the nerve repairs, and is less complete where compression has been severe or long-standing. Grip strength dips for a few weeks and then recovers.
Tenderness at the base of the palm — pillar pain — is common for a couple of months and settles. Fingers are moved from the start to prevent stiffness; heavy gripping and lifting wait. Most office work resumes within one to two weeks and heavier manual work later.
If it is both hands, or keeps coming back
Bilateral symptoms shift the emphasis from the wrist to the person. The question becomes what is making the tendon linings swell, and the answers are mostly systemic: thyroid disease, diabetes, pregnancy, inflammatory arthritis, or weight.
Recurrence after a technically good operation is uncommon, and prompts a rethink: was the diagnosis right, is a second site of compression involved — the nerve can also be compressed higher up — or is there an underlying condition that has not been addressed?
A particular pattern worth flagging: carpal tunnel syndrome in both hands, appearing alongside unexplained heart or kidney problems, occasionally signals amyloidosis. It is uncommon, it is often diagnosed years late, and the hands can come first by a long way.
The order most people should follow
1. Confirm the pattern — thumb, index, middle, half the ring finger; worse at night; relieved by shaking.
2. Look for a cause — thyroid, diabetes, pregnancy, inflammatory arthritis.
3. Mild and recent — night splint for six to eight weeks, plus treating any cause found.
4. No better, or moderate — steroid injection, which also confirms the diagnosis.
5. Severe, constant numbness, weakness or wasting — surgical referral without a long trial of splinting.
If you have night-time numbness in one or both hands and nobody has checked your thyroid or examined the thumb muscles, that is the gap. You can request a callback or book a consultation.
Common questions
Do carpal tunnel splints actually work?
For mild and recent symptoms, yes. Worn at night, a splint holds the wrist straight and stops it curling during sleep, which is when the tunnel narrows most. Give it six to eight weeks. It is much less useful once numbness is constant or the thumb muscles have started to waste.
When is carpal tunnel surgery needed?
When numbness is constant rather than intermittent, when there is weakness or visible wasting at the base of the thumb, when nerve studies show severe compression, or when splints and an injection have not helped. Waiting in those situations risks permanent nerve damage.
How long does a steroid injection last for carpal tunnel?
Most people get substantial relief, typically lasting months rather than permanently. It is particularly useful when the underlying cause is going to resolve — in pregnancy, or while a thyroid problem is being corrected — and a good response also helps confirm the diagnosis.
Why does my hand go numb at night?
The wrist naturally curls during sleep, which narrows the carpal tunnel and increases pressure on the median nerve. That is why symptoms wake people and why shaking the hand relieves them, and it is also why a night splint is the usual first treatment.
Can thyroid problems cause carpal tunnel syndrome?
Yes. An underactive thyroid is a recognised cause, as are diabetes, pregnancy, obesity and rheumatoid arthritis. Checking thyroid function and blood sugar is reasonable in almost anyone presenting with it, particularly when both hands are affected.
Does carpal tunnel syndrome go away on its own?
Sometimes, particularly when it is caused by pregnancy or by a thyroid problem that is then corrected. Mild recent symptoms may settle with a night splint alone. Long-standing compression with constant numbness does not resolve by itself.
Sources
- NHS — carpal tunnel syndrome www.nhs.uk
- NIAMS — carpal tunnel syndrome www.niams.nih.gov
- MedlinePlus — carpal tunnel syndrome medlineplus.gov
- NHS — underactive thyroid www.nhs.uk
This article is general information and does not replace a consultation.