A ganglion cyst is a fluid-filled lump below the surface of the skin that appear on near joints and tendons. They usually do not cause any symptoms and often disappear on their own. Treatment ranges from observation to an outpatient surgery called a ganglionectomy.
A ganglion cyst (plural: ganglia) is a small, fluid-filled lump just below the skin. Ganglia usually form close to a joint. Most ganglion cysts are on the wrist, finger or foot.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Lots of people get ganglion cysts. Ganglia are some of the most common benign (noncancerous) masses that develop in the body’s soft tissues.
No one knows exactly what causes a ganglion cyst to start growing. Some theories indicate that a cyst may develop after something injures a joint, allowing tissue to leak or bulge out.
Currently, most researchers agree that ganglion cysts develop from mesenchymal cells at the synovial capsular junction as a result of the continuous micro-injury. Repetitive injury to the supporting capsular and ligamentous structures appears to stimulate fibroblasts to produce hyaluronic acid, which accumulates to produce the mucin "jelly-like" material commonly found in ganglion cysts
From what the medical community understands about ganglion cysts, anyone can get them. Certain factors may increase your chances of having one of these cysts:
A bump beneath the skin is the main sign of a ganglion cyst. This bump can vary in size and shape. It may grow larger over time or when you use that area (joint) more. The cyst may not bother you at all. If you do have symptoms, you may notice some muscle pain or a tingling sensation. This is usually mass effect, which means that the mass is causing pressure and may cause inflammation.
Ganglion cysts usually appear at specific joints. Using the joint near the cyst may increase swelling and worsen any discomfort you feel.
Ganglion cysts typically develop on the:
A ganglion cyst usually looks like a lump or bump on your wrist, finger or foot. This lump may look symmetrical (round) or misshapen (more like an oval).
A ganglion cyst sits just below the skin’s surface. It may look like a bubble blown from a joint. Ganglia sometimes have a translucent effect (you can see through the lump at certain angles).
People experience ganglion cysts differently. Ganglia are usually (but not always) firm to the touch. Some people report that the fluid-filled cysts as soft. The lump likely moves easily under your skin.
Healthcare providers usually diagnose ganglia by physically examining you. A lump’s appearance and location (such as on the wrist or fingers) are telltale signs of ganglia. Your provider may press on the bump to see if it bothers you. Or they may shine a light on the lump to see if it’s translucent (partly see-through).
In some cases, your provider may remove a sample from inside the lump (called a biopsy) for further analysis. Ganglia usually contain a jellylike fluid, not solid tissue. In rare cases, your provider may recommend an X-ray to learn more about what’s causing your symptoms.
Your provider may use ultrasound to tell the difference between a solid mass and a cyst. There is also a difference between a ganglion cyst and a synovial cell. The difference is in the make-up of the lining of the cyst.
Some ganglion cysts are so small that they don’t cause obvious physical swelling, but they still cause pain. They are known as occult ganglions. Your healthcare provider may order a magnetic resonance imaging (MRI) test or an ultrasound to reveal them.
If a ganglion cyst doesn’t bother you, it might not need treatment. Sometimes a ganglion cyst goes away on its own.
Your provider may recommend treatment if a ganglion cyst:
Ganglia cyst treatments include:
Your provider may consider surgery if other treatments don’t provide relief or your cyst comes back. Surgeons treat ganglia by removing the entire cyst. A cyst often includes a stalklike structure (root) attached to the cyst.
Your surgeon may use open (traditional) techniques or arthroscopy (tiny incisions). In some cases, surgeons may take some tissue from the nearby joint to fully repair the problem.
Surgery to remove a ganglion cyst is called ganglionectomy. It is usually an outpatient procedure. That means you should get to go home the day of surgery. Full recovery takes two to six weeks. Orthopedic surgeons receive specialized training to perform intricate procedures on the body’s joints and other soft tissues.
Surgery may effectively resolve your symptoms. Having a ganglion cyst surgically removed greatly reduces the risk of a cyst coming back. Still, ganglia come back after surgery in an estimated 5% to 15% of cases.
You can’t prevent a ganglion cyst. Medical experts don’t know what causes them to develop.
Ganglion cysts are not dangerous. They are benign masses, which means they will not spread to other areas. Ganglion cysts are not cancer.
While some ganglion cysts may be painful, they pose no serious threat to your health.
If you have a ganglion cyst, you may want to ask your healthcare provider:
A note from Cleveland Clinic
If you have a ganglion cyst, you may not need treatment right away. If the lump doesn’t bother you, your provider may follow you over time to check for any concerning changes. Ganglion cysts are benign, which means these lumps aren’t cancer. They pose no long-term threat to your health. Many ganglion cysts go away on their own. If a ganglion cyst affects your quality of life in any way, ask your provider about treatment options. Splints, over-the-counter pain medication or surgery may provide relief.
Last reviewed by a Cleveland Clinic medical professional on 11/23/2020.
Learn more about our editorial process.