What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome (CTS) is a condition that causes numbness, tingling, and sometimes pain in the hand and fingers. It is caused by compression of the median nerve as it passes through the carpal tunnel — a narrow passageway in the wrist. CTS is one of the most common nerve disorders, affecting millions of people.
Causes and Risk Factors
- Repetitive hand and wrist movements (e.g. typing, using a mouse)
- Pregnancy (due to fluid retention)
- Obesity
- Diabetes
- Underactive thyroid (hypothyroidism)
- Rheumatoid arthritis
- Wrist injuries or fractures
- Family history of CTS
Symptoms
- Numbness, tingling, or "pins and needles" in the thumb, index, middle, and ring fingers
- Pain in the hand and wrist, sometimes extending up the arm
- Weakness in the hand — difficulty gripping objects
- Symptoms often worse at night or after prolonged hand use
- Dropping things
Treatment
Treatment depends on the severity of symptoms. Mild to moderate cases often improve with conservative measures:
For severe or persistent cases, carpal tunnel release surgery is highly effective. This involves cutting the ligament pressing on the median nerve to relieve pressure.
- Wrist splints — worn especially at night to keep the wrist in a neutral position
- Corticosteroid injections — to reduce inflammation
- Physiotherapy exercises
- Avoiding activities that worsen symptoms
- Treating underlying conditions (e.g. managing diabetes)
What it feels like day to day
Carpal tunnel syndrome usually creeps in. Many people first notice tingling or numbness in the thumb, index and middle fingers when they wake, and find themselves shaking the hand to get the feeling back. Holding a phone, a book or a steering wheel for a while can bring it on. The little finger is usually spared, because a different nerve supplies it.
As it progresses, fine tasks such as doing up buttons, picking up coins or opening jars can become clumsy, and you may drop things. In longer-standing cases the muscle at the base of the thumb can become thinner and weaker.
Why arthritis and carpal tunnel often go together
The carpal tunnel is a tight space, so anything that takes up room inside it can squeeze the median nerve. Inflamed tendon linings in rheumatoid arthritis, bony changes in wrist osteoarthritis, fluid retention in pregnancy, and conditions such as diabetes and an underactive thyroid can all play a part. If you have inflammatory arthritis and new carpal tunnel symptoms, tell your rheumatology team, because it can be a sign of active inflammation at the wrist.
How it is diagnosed
Your GP or physiotherapist will usually diagnose carpal tunnel syndrome from your symptoms and a hand examination, which may include simple tests that press on or stretch the nerve. If the diagnosis is unclear, symptoms are severe, or surgery is being considered, you may be referred for nerve conduction studies, which measure how well signals travel along the nerve. Blood tests can check for linked conditions such as diabetes or thyroid problems.
Things you can try first
Mild to moderate symptoms often improve without surgery, especially when started early.
- A wrist splint worn at night keeps the wrist straight and takes pressure off the nerve. Many pharmacies sell them, and physiotherapists can advise on fit.
- Notice what brings symptoms on. Take breaks from gripping or repetitive tasks, and keep your wrist in a neutral position when typing or using tools.
- Try gentle nerve and tendon gliding exercises taught by a physiotherapist or hand therapist.
- Avoid sleeping with your wrists tightly curled under your pillow or body.
- Managing linked conditions, such as keeping diabetes or thyroid problems well controlled, can help.
Steroid injections and surgery
If splints and activity changes are not enough, a steroid injection into the carpal tunnel can reduce swelling and ease symptoms. For some people the relief is lasting, for others it wears off.
Carpal tunnel release surgery cuts the ligament that forms the roof of the tunnel, giving the nerve more room. It is usually done as a day case under local anaesthetic. Surgery is generally considered when symptoms are severe, keep coming back, or there are signs of lasting nerve damage such as constant numbness or muscle wasting. Recovery involves keeping the hand elevated and moving your fingers early, with a gradual return to heavier gripping over the following weeks.
When to get help quickly
Book a GP or physiotherapy appointment if symptoms are stopping you sleeping, are there most of the time, or you notice weakness or wasting at the base of your thumb. Seek urgent medical help if numbness or weakness comes on suddenly, affects your face, arm or leg as well as your hand, or follows a significant wrist injury, as these need checking straight away.
About this page
Written by Louis Maxwell, First Contact Practitioner (HCPC PH128483), and pending clinical review. This is general information, not a diagnosis. Always follow the advice of your own GP, physiotherapist or rheumatology team. For emergencies call 999; for urgent advice use NHS 111.