Why does carpal tunnel syndrome cause hand numbness?

The carpal tunnel is a narrow passage at the wrist containing the median nerve and tendons. Swelling or reduced space can press on that nerve, interfering with messages between the hand and brain. You may feel tingling, reduced sensation, burning, or numbness in the thumb, index finger, middle finger, and part of the ring finger. Symptoms may be worse at night or when the wrist stays bent.

Notice when symptoms start and whether activities such as typing, driving, or holding a phone bring them on. Keep the wrist in a neutral position, take movement breaks, and avoid leaning on the palm. A clinician can examine sensation and strength and may recommend a night wrist splint, activity changes, physiotherapy, or other treatment based on the findings.

Arrange an assessment if numbness keeps returning, disturbs sleep, affects everyday tasks, or does not settle with simple changes. Seek prompt medical care for increasing weakness, loss of feeling that does not improve, or difficulty using the hand, because ongoing nerve pressure can affect hand function.

Ask which parts of the hand are affected, whether your pattern fits median-nerve irritation, and whether you need tests to check nerve function. You can also ask how long to try a wrist splint and which activities should be modified.