Ganglion cyst

Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

A ganglion cyst is a lump under the skin, usually surrounding a joint. It may cause some pain or irritation but isn’t harmful. Discover the symptoms and treatments available.

What is a ganglion cyst?

A ganglion cyst is a harmless lump under the skin which is filled with fluid. This is called synovial fluid, which is present around joints and tendons to help them move day to day.

What are the symptoms of a ganglion cyst?

You may notice a small lump on your:

  • Hand including the palm, wrist, finger (commonly on the finger joint), thumb or knuckle

  • Foot including the ankle, top of the foot or toe

  • Knee 

  • Collarbone

These cysts can range in size – anything from the size of a pea to the size of a ping-pong ball. This often depends on the amount of movement in your joint. 

Most people with a ganglion cyst experience no pain. Some pain might be felt if the swelling presses against ligaments, nerves or a blood vessel. Most commonly, you may feel:

  • Tenderness

  • Irritation

  • Tingling at the site of the cyst

  • Restricted movement in your joint

What causes a ganglion cyst?

Ganglion cysts start forming when fluid leaks out from a joint. This fluid collects and forms a cyst. It’s not known why this happens, but it’s thought to be because of trauma or arthritis of the joint.

Who is at risk of a ganglion cyst?

The risk of developing a ganglion cyst is higher if you’re female. The most common age to develop one is usually between 20 and 40 years.

How is ganglion cyst diagnosed?

When you see a doctor about your cyst, they may want to examine you. They’ll apply pressure to the cyst to test for any pain or tenderness, and in some cases, you may be referred for some imaging tests such as x-ray, MRI or ultrasound. This is done to rule out any other conditions.

How to treat a ganglion cyst

It’s not always recommended to treat a ganglion cyst. If the cyst is painless and has little effect on your daily activities, it’s likely you’ll be advised to watch and wait. Putting pressure over the cyst will not resolve it. 

If you’re experiencing discomfort because of your ganglion cyst, it may be necessary to remove it. Removal methods include:

Aspiration – This is a procedure where fluid is drained from the cyst. While this treatment causes the swelling to go down, unfortunately, in about a half of cases,  it does not stop the cyst from coming back.

Surgery – If your ganglion cyst is removed with surgery the chances of it coming back are greatly reduced. Surgery is either by keyhole or open surgery. You’ll need to speak to a doctor about options before surgery is recommended.

Never try to ‘pop’ or remove a ganglion cyst yourself – it’s always best to allow a doctor to drain the cyst. This will avoid excessive damage to the joint.

When should I seek help?

If you notice a lump, book an appointment with a doctor to get it examined and rule out any other conditions. 

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi