What is a wrist ganglion?

A ganglion cyst is a pocket of joint fluid (figure). Half of all wrists have a pocket of fluid detected on magnetic resonance imaging. Ganglions that can be seen and felt are most common on the back of the wrist. The fluid comes from a connection to the wrist joint (figure).

Ganglion cysts look funny, but they are harmless. If you have more than a little pain, it is probably not from the ganglion. You may feel a little discomfort when you put pressure on the wrist with it extended, like when doing a push-up or opening a heavy door, but other pains are probably from something else.

Figure: a gagnlion cyst.

Figure: ganglion cyst and wrist joint.

Signs and symptoms
Ganglions can feel as hard as a bone. The size may go up and down.

Evaluation
A visible, firm lump on the wrist in a characteristic location is nearly always a ganglion cyst.