Ganglia are swellings that occur over joints or on coverings of tendons in the hands and wrists and that contain a jellylike fluid.
It is not known why ganglia develop.
Ganglia usually do not cause symptoms.
Doctors base the diagnosis on an examination.
If ganglia do cause symptoms, the fluid is withdrawn using a needle or the ganglion is surgically removed.
Ganglia typically spontaneously occur in people between the ages of 20 and 50. Women are affected 3 times more often than men. Ganglia usually develop on the back of the wrist. Ganglia also develop on the front of the wrist and on the back of the finger, a few millimeters behind the cuticle (where they are also called mucous cysts).
Why ganglia develop on the wrist is not known, although they may be related to a previous injury. Ganglia on the back of a finger usually are related to arthritis of the last joint of the finger. However, in most cases, having a ganglion cyst does not mean that arthritis will develop.