What Is Carpal Tunnel Syndrome?

Why do your thumb, index, and middle fingers keep tingling — especially at night, when you're not even doing anything with your hands? For a lot of people, that odd, half-asleep feeling is the first sign of carpal tunnel syndrome. The short video at the top of this page, from the Mohamed Ibrahim channel, walks through the condition in plain terms: what it feels like, and why it happens at the wrist. The questions below follow the ones patients tend to ask next.

What is actually being squeezed in there?

Running through your wrist is a narrow passageway called the carpal tunnel. Tendons pass through it, and so does the median nerve — the nerve that gives feeling to the thumb side of your hand and helps control some of the small muscles at the base of the thumb. The tunnel can't stretch much, so when the tissue inside it swells or thickens, the nerve is usually what pays the price. Press on a nerve and it complains in its own language: tingling, numbness, a burning or aching feeling, and sometimes a hand that feels clumsy or weaker than it should. It isn't worn-out joint cartilage of the kind behind a knee replacement — it's a nerve-space problem, not a joint-surface problem.

Why does it wake people up at night?

Good question, and a common one. Many of us sleep with our wrists bent without realising it, and a bent wrist raises the pressure inside that already-tight tunnel. So symptoms often flare in the small hours, and people describe shaking or flicking the hand to get the feeling back. During the day, the same tingling may show up while holding a phone, reading, driving, or doing work that keeps the wrist in one position for a long stretch. Symptoms that come and go early on can become more constant if the pressure on the nerve continues, which is why the video above stresses that early assessment matters.

How does a clinician check whether this is it?

It usually starts with your story: which fingers are involved, when it happens, and what seems to set it off. A clinician may examine feeling and strength in the hand, and gently reproduce the pressure — for example by holding the wrist in a bent position or tapping over the nerve — to see whether your familiar symptoms appear. Sometimes further tests are suggested to measure how well the nerve is conducting, or to rule out a different cause of hand numbness. You don't need to self-diagnose from a checklist; the pattern of symptoms is a clue, not a verdict.

What can be done about it?

That depends on how severe it is and how long it's been going on. For milder cases, simple measures are often discussed first: keeping the wrist straighter at night with a splint, and easing off the positions or activities that reliably provoke symptoms. If those aren't enough, a clinician may talk through other options, which can include an injection around the tunnel or, where pressure on the nerve needs to be relieved directly, a release procedure that opens the tight ligament forming the tunnel's roof. If you'd like to see what that involves, this site's open carpal tunnel release video shows the operation being performed. Which route makes sense is an individual decision, made with the clinician who has examined your hand.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician and researcher.

Frequently Asked Questions

Which fingers does carpal tunnel syndrome affect?
Typically the thumb, index, and middle fingers, and part of the ring finger — the area served by the median nerve. The little finger is usually spared, which is one clue clinicians use when sorting out the cause of hand numbness.

Can carpal tunnel syndrome go away on its own?
Mild symptoms sometimes settle, particularly when they're linked to a temporary strain or a position you can change. But symptoms that persist, keep waking you, or come with weakness are worth getting assessed rather than simply waited out.

Is surgery the only treatment?
No. Surgery to release the tunnel is one option, generally discussed when simpler measures haven't controlled symptoms or the nerve is showing strain. Many people start with a night splint and activity changes, guided by their clinician.

Educational only — this article is general information about carpal tunnel syndrome, not medical advice. Persistent numbness, tingling, or weakness in the hand should be assessed by a qualified clinician, who can confirm the cause and discuss treatment with you.