On the thumb side of your wrist and the back of your hand the tendons which run from your hand pass through small tendon sheaths. These tendons can become inflamed and swollen where they run in the tendon sheaths, and this is relatively common for the two tendons running to your thumb which pass through a sheath called the first dorsal compartment. When these two tendons become inflamed the tendon sheath also thickens and we call this condition DeQuervain’s tenovaginitis or tenosynovitis.
DeQuervain’s causes pain on the thumb side of your wrist which is worse when you deviate your wrist towards your little finger. It can cause marked pain and reduced function of your wrist. It is relatively common in women in the months following giving birth.