If DeQuervain's is diagnosed, that means your doctor has found a name for the pain and tenderness on the outside of your thumb. The pain might feel sharp, like a stabbing pain, and happens when you move your hand a certain way.
DeQuervain's may also cause difficulty for you when you are making a fist or trying to grip or grasp something. Since it can have several symptoms (pain, gripping difficulty) it is a "syndrome." A syndrome is a collection of symptoms.
Arthritis of the thumb can have similar symptoms. I suppose it's possible that they have much the same cause. Muscles cause arthritis (some muscles too "tight" and some too "weak--they pull on the joint and cause bony changes.) Arthritis is caused by using the body in an out-of-neutral position and DeQuervain's is caused by excessively tilting the hand at the wrist, which would also be out-of-neutral position.
What is it? Apparently, it's not a true "itis" or inflammation of the tendons, although many doctors call it "tendonitis." More likely, it's an irritation of the tendons at the base of your thumb. The tendons pass through a tough band of tissue. According to David Nelson MD, restrictions occur while the tendons are passing through this band, possibility because of thickened tissues and increased blood flow.
Does a brace help? There are some braces which prevent the thumb from moving and the wrist from tilting. They may help by eliminating the ability of your wrist to tilt from side to side, but when they are no longer being used, your pain may come back. If a brace can "train" you to do a movement correctly, rather than tilting, then perhaps it's good to wear for those times when you do the "wrong" thing. They cost approximately $23 to $30 and it looks like they do keep your thumb from moving, too, so you'd just have to try and see if it would work for you.
What about surgery? Surgery is available, of course. The surgeon cuts the band of tough tissue so the tendons can move freely. Apparently, sometimes they can move TOO freely because sometimes when a patient flexes or extends their wrist fully--and at the same time does forceful movements of their thumb--the tendons that are no longer contained by the band of tough tissue can pop out of position. Any surgery can have side effects, and even though this one is usually done on an out-patient basis, many patients report quite a bit of pain afterward, much more than they expected.
Dr. Nelson says that steroid (cortisone) injections (shots) are helpful in about 82% to 95% of the patients.
How is it diagnosed? Easy. If you tuck your thumb into your hand, and tilt your hand in the direction of your baby finger (toward the outside of your arm) and it hurts, you have just make the diagnosis.
What causes deQuervain's? There are 3 movements your wrist can make. 1) bending forward, or palm-ward, 2) bending backward, or toward your elbow, 3) tilting side to side or from the thumb side to the baby finger side (and baby to thumb.)
Doing fairly equal amounts of the 2 bending movements is okay. The wrist is called a "hinge" joint. That means it's made to move in those directions. But the tilting movement, well, it's not built to move that way too often and therein lies the problem.
Some people have a job that causes them to tilt their hand a lot and that aggravates those tendons. Some people do things in a way that they don't have to, and that causes tendon irritation, too.
I'm thinking of a hospital worker who ripped