Ganglion Cysts


A ganglion is a small sac (cyst) filled with clear, jellylike fluid that often appears as a bump on the hands and wrists. Ganglion cysts are usually small and round and can feel soft or firm or rubbery to the touch.

Most patients notice that the cysts appear suddenly. They may grow as activity increases, because more fluid collects in the sac. Ganglion cysts are not cancerous.


The cause of ganglions is not known, but it may be a reaction to an injury that causes the tendon sheath (which covers the tendon) or joint capsule (which protects the joint) to form extra fluid and balloon out.


Ganglion cysts are often painless, but depending on location, they may cause enough discomfort to need treatment. If a ganglion cyst presses up against a nerve it can cause symptoms that include numbness, tingling, a weakened grip and a reduced range of motion.


ValleyOrtho’s physicians can diagnose a ganglion cyst based on what it looks like, whether it feels tender when pressure is applied, and its location. Because a ganglion cyst is filled with fluid, the physician may also shine a small light, such as a pen light, through it to confirm that it is a ganglion cyst. If a diagnosis is still not certain, the physician may order an X-ray to rule out more serious medical conditions, or an ultrasound to confirm that the lump is a cyst.


Often, ganglion cysts can be resolved with nonsurgical techniques such as splinting and anti-inflammatory medication. Ganglion cysts may resolve on their own, but if a ganglion cyst is painful, causes pressure on a nerve, or limits activity, it may need to be drained (aspirated), or surgically removed.