Ganglion is a cyst formed from synovium, which is a tissue lining a joint or tendon. The main function of synovium is to produce lubricating fluid for joint. A ganglion is filled with a thick jelly-like fluid. Local trauma to the tendon or joint can result into ganglia. But many a times they are formed for reasons not clearly understood. Ganglia may be an early signs of arthritis. Ganglia are most frequently found in the wrist and ankles. They are painless and clearly visible as localized swellings. A ganglion can spontaneously rupture and go away. People with a persisting or recurring ganglion should be evaluated for signs of systemic forms of arthritis, such as rheumatoid arthritis. Ganglion cysts are noncancerous in nature. A ganglion cyst may develop suddenly or gradually over time.

Ganglion cysts generally are:

• Raised lumps near your wrist or finger joints
• Fixed in one place but may "give" a little when you push against them
• A little more than an inch (3 centimeters) in diameter.
• Variable in size depending on your activity level, becoming larger when you use the affected joint and growing smaller when you're at rest
• Painless, although in some cases the cysts may put pressure on the nerves near the joint, which can cause pain, weakness or numbness in your hand

• Regular, repetitive movement that stresses your wrist or hand.
• Having osteoarthritis,
• njury to the joints or tendons of your hands or feet.