Ganglion cyst

A ganglion cyst is a fluid-filled swelling that usually develops near a joint or tendon. Cysts can range from the size of a pea to the size of a golf ball. They’re harmless but can sometimes be painful.

Causes of a ganglion cyst

Ganglion cysts look and feel like a smooth lump under the skin. They're made up of a thick, jelly-like fluid called synovial fluid. This fluid surrounds joints and tendons to lubricate and cushion them during movement.

Ganglions can occur alongside any joint in the body.

They most commonly form on:

•    the wrist (particularly the back of the wrist)
•    hands
•    fingers

Ganglions are harmless, but can sometimes be painful. If they don't cause any pain or discomfort, they can be left alone and may disappear without treatment. Although this can take a number of years.

It's not clear why ganglions form. They seem to occur when the synovial fluid that surrounds a joint or tendon leaks out and collects in a sac.

Treatment for a ganglion cyst

Treatment is usually only recommended if the cyst causes pain or affects the range of movement in a joint. The two main treatment options for a ganglion cyst are:

•    draining fluid out of the cyst with a needle and syringe (aspiration) - usually carried out in the outpatient department of your local hospital or GP surgery
•    cutting the cyst out using surgery – this will be done in hospital 

Treatment for ganglion cysts is usually only carried out if they:

•    cause significant pain
•    disrupt daily activities

If you want a cyst removed for cosmetic reasons, you may have to pay for private treatment.


Having a ganglion cyst removed is a minor procedure, so complications are rare and seldom serious. However, a small number of people experience permanent stiffness and pain after surgery.

If you have the operation under general anaesthetic, there's also a very small risk of complications to your heart and lungs. Pre-assessment tests before surgery should make sure your risks are as low as possible.

There's always a chance a ganglion cyst will come back after treatment. This is more likely if the ganglion is on certain areas of the wrist.

•    Find out more about ganglion cysts on the NHS website

The information on this page has been adapted from original content from the NHS website.

For further information see terms and conditions.

This page was published May 2018

This page is due for review May 2019

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