Ganglions are small sacs (cysts) filled with fluid that often appear as bumps on top of joints or tendons at the back of the hand, wrist joint and palm side of the wrist.
Most people with ganglion cysts notice that the bumps appear suddenly. Bumps may be very small like a pea or bigger than a cherry. Ganglions may get bigger as activity increases and more fluid collects in the sac, as it grows it can cause pain by pressing on a nearby nerve.
Anyone can get a ganglion: adults between 15 and 40 years old are most likely to be affected. Those who have osteoarthritis and/ or joint or tendon injury can also have ganglion cyst.
What causes ganglions?
Experts don’t know the exact cause of ganglions. They may be linked to:
- Inflammation or irritation of the tendon sheath or joint capsule.
- An injury.
- Overuse or repetitive motions, such as those you do at work.
- A common type of ganglion called a mucous cyst ganglion occurs with arthritis of the hands. It usually affects the joint nearest the fingernail.