DeQuervain's syndrome is when the two tendons that move your thumb become thickened. These two tendons lie together in a small compartment in the outer part of your thumb, just below your wrist. The changes are due to excessive thumb and wrist movement which creates friction, irritation and swelling of the tendons and their supporting sheath. It is usually associated with repetitive activity. It is also common after having a baby when new forces through your thumb and wrist occur with lifting your baby. DeQuervains Release (surgery) involves releasing the first dorsal compartment so there is more space for the tendons to move.