Is it carpal tunnel or de Quervain's tenosynovitis?

Numbness in the thumb, index and middle fingers, especially at night, points to carpal tunnel syndrome. Ache at the base of the thumb, on the wrist side, that flares with gripping, pinching or texting points to de Quervain's tenosynovitis. Both involve the thumb, so the most useful check is whether the thumb feels numb or aches, and exactly where the pain sits.

Numbness is the carpal tunnel sign, and de Quervain's is an ache

Carpal tunnel syndrome squeezes the median nerve at the wrist. That nerve gives feeling to the thumb, index and middle fingers and half of the ring finger ¹. Numbness and tingling in those fingers, often waking you at night, is the usual pattern ².

De Quervain's is a tendon problem. OrthoInfo describes it as a painful condition in which the thumb-moving tendons become irritated inside the narrow tunnel between the wrist and the thumb ³. Its typical symptoms are ache and tenderness at the base of the thumb, worse with pinching and gripping. Numbness is not its main feature, so numb fingers point away from de Quervain's and toward the nerve.

Texting and typing can make de Quervain's worse

The cause of de Quervain's is not completely understood, but OrthoInfo says the condition can be worsened by movements of the wrist and thumb, including typing and texting ⁴. That makes it the thumb condition most often linked to a keyboard or phone.

The evidence for the phone link comes from a survey. In a 2014 survey of physical therapy students in Karachi, 149 students, almost half of those surveyed, had a positive Finkelstein test, the bedside screen for de Quervain's ⁵. The students were a convenience group, so the survey shows an association with texting, not a cause.

A cohort of computer users found that de Quervain's tendonitis was the most common hand or arm disorder in that group ⁶. For a typist, that makes de Quervain's a more direct candidate than carpal tunnel when the pain is at the base of the thumb.

A bedside test and an examination separate the two

The Finkelstein test is the usual bedside check for de Quervain's. The thumb is tucked into the palm and the wrist is moved toward the little finger, and pain on that movement points to the thumb tendons. A clinician also checks sensation and grip strength, since carpal tunnel can weaken the thumb. The NHS lists a weak thumb or difficulty gripping among the symptoms of carpal tunnel ⁷.

Where the signs overlap, the diagnosis rests on history and examination together, because no single test is decisive for carpal tunnel. If the examination leaves doubt, nerve conduction testing can confirm carpal tunnel ⁸.

What to do

1. Note the pattern. Numb fingers at night point to the nerve. A sore spot at the base of the thumb that hurts when you pinch points to the tendon.
2. Reduce pinching and gripping. Repeated thumb work can aggravate the pain, so a short break from texting and tight grips is a sensible first step.
3. See a GP if the numbness persists, the grip weakens, or the thumb pain does not ease.
4. Know the timeline for surgery. OrthoInfo says surgery may be recommended for de Quervain's if symptoms are severe or do not improve after 6 weeks of nonsurgical treatment ⁹.

If you type for hours, moving some of that work to your voice means less typing for the thumb and wrist. Dictation for RSI and carpal tunnel explains how to switch parts of the work, and hand and wrist pain from typing sets out the other causes. For the nerve condition, see the carpal tunnel syndrome guide and the carpal tunnel treatment guide. The accessibility and health overview covers the wider subject. If the ache is over a moving tendon elsewhere in the hand, check the tendonitis comparison, and for the condition itself read the de Quervain's tenosynovitis entry and the median nerve entry.