A ganglion cyst is a collection of fluid on a joint or tendon (the tissue that connects muscles and bones). They usually appear on the backs of hands, fingers and wrists, and can also occur on the feet, ankles and knees.
The cause of them is not known, however it is thought they may be caused by tiny tears in the covering of a tendon or joint. Ganglion cysts are benign, meaning they are not cancerous.
Ganglion cysts symptoms
A ganglion cyst looks like a smooth lump under the skin, ranging in size from the size of a pea to the size of a golf ball. Occasionally they might not be visible at all.
Most ganglion cysts do not cause symptoms, but sometimes they cause:
- difficulty moving the affected area
- a pinched nerve
Ganglion cysts diagnosis
If you think you have a ganglion cyst, it is important to see your doctor to make sure that the lump is not a symptom of another illness. An examination by your doctor is generally all that is needed.
Other possible tests include:
- removing some of the fluid with a syringe
- ultrasound to find out whether the lump is solid or filled with fluid
- MRI to examine any cyst that is not visible
Ganglion cysts treatments
Many people with ganglion cysts never bother having them treated. Sometimes they go away by themselves after a couple of years.
Treatment isn’t necessary unless a cyst is causing pain or making it difficult to move the affected part of your body.
If you do need treatment, here are some options:
- Using a needle to drain the fluid out of the cyst (aspiration). This is a painless procedure that can be done in your doctor’s office or in a hospital outpatient department. Roughly half of ganglion cysts removed this way will come back.
- Surgery to cut out the cyst. This is a simple procedure that can be done under local or general anaesthetic. A small number of people have ongoing pain and stiffness in the area after surgery.
The traditional method of treating a ganglion cyst involves hitting it hard with a heavy book. This is not a good idea. It might burst the cyst, but it might cause other injury.
Last reviewed: January 2018