What is DeQuervain's Tendinitis?

DeQuervain's tendinitis is a condition brought on by irritation or swelling of the tendons found along the thumb side of the wrist.  The irritation causes the compartment (lining) around the tendon to swell, changing the shape of the compartment; this makes it difficult for the tendons to move as they should. The swelling can cause pain and tenderness along the thumb side of the wrist, usually noticed when forming a fist, grasping or gripping things, or turning the wrist.

What causes it? The cause of deQuervain's  tendonitis is an irritation of the tendons at the base of the thumb.  For example, awkward hand positions required by a new mother in caring for an infant is a common cause of this condition.