Carpal Tunnel Syndrome

Carpal tunnel syndrome is compression of the median nerve as it passes through the carpal tunnel in the wrist, causing numbness, tingling and weakness in the hand.

Carpal tunnel syndrome usually begins gradually, and the pattern of symptoms is often more telling than their severity.

Numbness and tingling affect the thumb, index and middle fingers, and the thumb-side half of the ring finger. The little finger is typically spared, because it is supplied by a different nerve. Many patients notice this distinction only when it is pointed out.

Symptoms are characteristically worse at night and frequently wake people from sleep. Shaking the hand or hanging it over the edge of the bed often brings relief within a minute or two.

Daytime symptoms tend to appear during sustained gripping or with the wrist held still: driving, holding a book or phone, using a keyboard, or cycling.

As the condition progresses, numbness becomes more constant and less easy to shake off. Some patients describe clumsiness rather than numbness, dropping objects or fumbling small items such as buttons and coins. Weakness or visible thinning of the fleshy muscle at the base of the thumb is a later sign and should prompt earlier assessment.

Pain may be felt in the hand and can radiate into the forearm. Pain that dominates the picture, or that follows a different distribution, raises the possibility of another diagnosis.

The carpal tunnel is a narrow passage on the palm side of the wrist. Its floor and sides are formed by the carpal bones, and its roof by a thick band of tissue called the transverse carpal ligament. Nine flexor tendons and the median nerve pass through this fixed space.

Because the tunnel cannot expand, anything that increases pressure inside it compresses the median nerve, which is the most vulnerable structure present. Sustained pressure interferes first with the nerve's blood supply and, over time, with the insulating myelin around its fibres. This is why symptoms are initially intermittent and fully reversible, and why long-standing compression recovers more slowly.

In most patients no single cause is identified. Recognised contributing factors include:

Anatomy: a constitutionally narrow tunnel, which helps explain why the condition often runs in families and why it is frequently bilateral.

Hormonal and metabolic factors: pregnancy, thyroid disease and diabetes. Pregnancy-related symptoms often settle after delivery.

Inflammatory conditions: rheumatoid arthritis and other conditions causing swelling of the tendon linings within the tunnel.

Previous injury: a distal radius fracture or other wrist trauma that alters the shape or volume of the tunnel.

Occupational and activity factors: prolonged, forceful and repetitive hand use, particularly combined with vibration or sustained awkward wrist positions. The relationship with ordinary keyboard work is weaker than is commonly assumed.

Arrange a specialist assessment if:

Numbness or tingling has been present for more than a few weeks, or is waking you at night regularly.

Symptoms are no longer intermittent and some numbness is present most of the time.

You have noticed weakness of grip or pinch, difficulty with buttons, keys or coins, or you are dropping things.

The fleshy muscle at the base of your thumb looks flatter than on the other side.

Symptoms have not improved after a reasonable trial of night splinting.

You are pregnant and symptoms are severe enough to disturb sleep, so that appropriate non-surgical measures can be arranged.

Seek assessment promptly rather than waiting if numbness has become constant or if there is visible muscle wasting. Nerve fibres recover more reliably when compression is relieved before this stage, and delay can leave permanent sensory or strength deficits.

The diagnosis is made clinically. Dr. Safwat will begin with the history, because the pattern and timing of symptoms carry more diagnostic weight than any single test: which fingers are affected, whether symptoms wake you, what relieves them, and how function has changed.

The assessment covers the whole upper limb, not only the wrist. Nerve compression at the neck or elbow can produce overlapping symptoms, and the two can coexist. A cervical spine problem, cubital tunnel syndrome and carpal tunnel syndrome are distinguished largely on examination.

Where symptoms are longstanding, both hands are examined and compared, since bilateral involvement is common and the less symptomatic side is often affected too.

Investigations support the clinical diagnosis; they do not replace it.

Nerve conduction studies measure how well the median nerve conducts signals across the wrist. They help confirm the diagnosis, grade severity, and identify compression elsewhere. They are particularly useful when the picture is atypical, when both hands are affected, or before surgery. Results should always be interpreted alongside symptoms and examination: studies can be normal in genuine early carpal tunnel syndrome, and mildly abnormal in people without symptoms.

Ultrasound can show swelling of the median nerve at the wrist and is useful for identifying a space-occupying cause such as a ganglion or thickened tendon lining. It is quick and comfortable.

Blood tests are arranged only where the history suggests an underlying cause such as thyroid disease or diabetes.

X-rays are not needed for carpal tunnel syndrome itself, but may be used if there has been previous wrist injury or if arthritis is suspected.

Non-surgical treatment is appropriate for mild and moderate symptoms, and is often the sensible starting point.

Night splinting is the mainstay. A splint holds the wrist in a neutral position overnight, preventing the sustained bending that raises pressure inside the tunnel during sleep. It needs to be worn consistently for several weeks before judging the result, and it works best for symptoms that are predominantly nocturnal.

Activity modification means adjusting sustained gripping, vibration exposure and wrist posture where practical, rather than stopping activity altogether.

Corticosteroid injection into the carpal tunnel reduces swelling around the nerve and often produces marked, though frequently temporary, improvement. A good response is also useful diagnostic information. Repeated injections are not advisable.

Treating an underlying condition, such as thyroid disease, may improve symptoms.

Hand therapy including nerve gliding exercises can help some patients, usually alongside splinting rather than instead of it.

If symptoms return each time non-surgical measures are withdrawn, or if numbness is becoming constant, surgery is usually the more durable answer.

Surgery is considered when:

Symptoms persist or recur despite splinting, activity modification and, where appropriate, injection.

Numbness has become constant rather than intermittent.

There is measurable weakness of thumb function, or thinning of the muscle at the thumb base.

Nerve conduction studies show moderate or severe compression.

Sleep is being disturbed regularly enough to affect daily life.

The decision is not made on test results alone. A patient whose sleep is broken every night by numbness may reasonably choose surgery with only moderate study findings; another with abnormal studies but easily controlled symptoms may reasonably wait.

Where there is established muscle wasting or constant numbness, surgery is advised without prolonged further delay. In that situation the aim is to halt progression and allow what recovery remains possible, and the extent of recovery is less predictable.

Carpal tunnel release relieves pressure by dividing the transverse carpal ligament, the tight roof of the tunnel. Once divided, the tunnel opens and the space available to the median nerve increases immediately. The ligament heals with a longer, looser span; it is not repaired.

The operation is a day case. You go home the same day.

Open release is performed through a short incision in the palm, in line with the ring finger, generally 2 to 3 cm long. The ligament is divided under direct vision. This allows the nerve to be inspected and any other cause of compression to be addressed.

Endoscopic release uses one or two smaller incisions and a camera to divide the ligament from within the tunnel. Discomfort in the palm may settle a little sooner in the early weeks. Longer-term results of the two techniques are broadly comparable.

The choice depends on your anatomy, the findings, whether previous surgery has been performed, and your own preference after discussion. Both aim at the same result.

The procedure typically takes around fifteen to twenty minutes. Skin is closed with sutures and a soft dressing applied. You will be asked to move your fingers immediately afterwards.

Recovery has two separate timelines: the wound, which heals over weeks, and the nerve, which recovers over months.

First 48 hours. Keep the hand elevated above heart level as much as possible; this does more to limit swelling and pain than anything else. Move the fingers fully and often from the day of surgery. Keep the dressing dry.

First two weeks. Light use of the hand for eating, dressing and writing is encouraged. Avoid gripping, lifting and pushing through the palm. Sutures are usually removed at around 10 to 14 days.

Two to six weeks. Grip strengthens gradually. Most desk-based work is comfortable well before six weeks; manual work generally is not.

Six weeks to three months. Scar tenderness settles. Pillar pain, an ache in the palm on either side of the scar when leaning on the hand, is common, expected, and usually resolves.

Three months onward. Continued improvement in strength and in sensation where the nerve was more severely affected.

Night symptoms often improve immediately, sometimes on the first night. Constant numbness present before surgery improves more slowly and less predictably.

Carpal tunnel release is one of the more reliable operations in hand surgery. The large majority of patients obtain lasting relief of night symptoms and of intermittent numbness.

What recovers well: night waking, tingling brought on by driving or holding a phone, and intermittent numbness. These often improve within days to weeks.

What recovers more slowly: constant numbness, reduced fine sensation, and weakness. Nerve fibres regenerate slowly, and improvement can continue for a year or more after surgery.

What may not fully recover: sensation and thumb muscle bulk lost through prolonged severe compression. Where the muscle at the thumb base has wasted significantly, surgery is expected to stop deterioration; restoration of bulk and strength is less certain.

Grip strength commonly dips for the first weeks after surgery before exceeding its pre-operative level.

Recurrence is uncommon. Persistent symptoms after surgery more often reflect severe pre-operative nerve damage, or a second site of compression, than failure of the release itself.

Carpal tunnel release is a low-risk procedure, but no operation is without risk.

Common and expected: scar tenderness for several weeks; pillar pain, an ache on either side of the scar when weight-bearing through the palm, usually settling within three to six months; temporary weakness of grip.

Uncommon: wound infection, usually superficial and treated with antibiotics; delayed wound healing; a thickened or sensitive scar; stiffness of the fingers, more likely if early movement is avoided.

Rare: injury to the median nerve or one of its branches, including the branch to the thumb muscles; injury to a digital nerve; incomplete division of the ligament requiring further surgery; complex regional pain syndrome, an uncommon condition causing disproportionate pain, stiffness and swelling; bleeding or haematoma.

Risks are discussed individually before surgery in the context of your own anatomy, general health and previous procedures.