Carpal tunnel syndrome

A nerve compressed at the wrist. Night pain is the giveaway, and a splint often solves it.

What it is

Carpal tunnel syndrome is compression of the median nerve as it passes through a narrow tunnel at the wrist. It affects around 1 in 20 people, more often women, and most commonly between 40 and 60.

It is associated with pregnancy, hypothyroidism, diabetes, rheumatoid arthritis and obesity, and checking for those is worth doing rather than treating in isolation.

The distinguishing feature is when it hurts. Carpal tunnel wakes people at night, and they shake the hand to relieve it. Almost nothing else does that in the same way.

Left long enough, the muscle at the base of the thumb wastes and the weakness does not fully recover, which is the argument for not waiting years.

Signs you might notice

Numbness, tingling and pain in the thumb, index, middle and half the ring finger. The little finger is spared, which is diagnostically useful.

Symptoms worse at night, waking the person, and relieved by shaking or hanging the hand down.

Worse with driving, holding a phone, or gripping.

Dropping things, and difficulty with buttons and jar lids.

Wasting of the fleshy muscle at the base of the thumb, which indicates it has been going on too long.

How it can affect day-to-day life

People put up with it for years, and the night waking is what eventually drives them to seek help. Chronic sleep disruption has its own costs.

In pregnancy it is common and usually resolves after delivery, so surgery is rarely needed.

The most useful and most under-used intervention is a night splint. Worn in neutral position overnight, it resolves or substantially improves a large proportion of cases, and it costs very little.

Supporting someone well

Try a night splint first, worn in neutral, for at least six weeks. This is the highest-value low-cost intervention.

Check for the underlying causes: thyroid, glucose, and inflammatory arthritis.

Adjust the workstation and take breaks from sustained grip and vibration.

Ask about a steroid injection, which helps many people and can avoid or delay surgery.

Do not wait years if there is constant numbness or thumb muscle wasting. Nerve damage at that stage may not fully recover after surgery.

Surgery is quick, done under local anaesthetic, and highly effective for confirmed carpal tunnel syndrome.

Where to get help

A GP or physiotherapist can assess and provide a splint; many areas allow self-referral to physiotherapy.

Constant numbness or wasting warrants earlier surgical referral and nerve conduction studies.

Arthritis UK have exercise and splint guidance.