Carpal tunnel syndrome

The carpal tunnel is a narrow passageway on the palm side of the wrist, bounded by bones and the transverse carpal ligament. The median nerve and nine flexor tendons pass through this tunnel. When the tunnel narrows or its contents swell, the median nerve is compressed — causing the characteristic symptoms of carpal tunnel syndrome (CTS).

**The median nerve** supplies sensation to the thumb, index, middle finger, and the thumb-side half of the ring finger. It also controls the thenar muscles that power thumb movement. Compression impairs both sensation and grip strength.

**Causes and risk factors:** - Medical conditions causing wrist swelling: diabetes, thyroid dysfunction, rheumatoid arthritis, fluid retention in pregnancy or menopause, hypertension - Repetitive wrist movements: typing, assembly line work, carpentry, use of vibrating tools, playing keyboard instruments - Poor wrist positioning at the keyboard or mouse - Women are three times more likely than men to develop CTS; most common between ages 30 and 60 - Lifestyle factors: smoking, high salt intake, sedentary lifestyle, high BMI, wrist fractures

**Symptoms:** - Numbness, tingling, and pain in the thumb, index, middle, and part of the ring finger - Burning pain that radiates up the arm - Wrist pain at night, waking from sleep; hands "fall asleep" - Weakness in the hand — dropping objects; reduced pinch and grip strength

**Untreated CTS** can progress to permanent nerve damage, persistent weakness, and permanent loss of hand function.

First-line management includes wrist splinting (especially at night), avoidance of aggravating activities, and treatment of any underlying medical condition. When these measures fail, injection therapies and physiotherapy are the next steps. Surgery (carpal tunnel release) is reserved for severe or persistent cases.