By EKalman July 7, 2025 - 7:35am

Finding a lump or bump on your body can be stressful, especially when you don’t know what it is. One common type of lump is called a ganglion cyst. These are usually harmless, but they can still cause concern, especially if they appear suddenly or grow in size.

Here are 10 important facts about ganglion cysts that can help you understand what they are, how they behave, and what you can do about them.

1. What Exactly Is a Ganglion Cyst?
A ganglion cyst is a non-cancerous lump filled with a thick, jelly-like fluid. It usually forms near joints or tendons, especially in the hands or wrists. These cysts are round or oval in shape and often show up as a bump under the skin. Although they may look concerning, ganglion cysts are generally not harmful.

2. They Can Happen at Any Age
Ganglion cysts are not limited to a certain age group. They can appear in children, teens, and adults. However, they tend to be more common in young adults, especially women. Men can also get them, but not as often.

3. Treatment Isn’t Always Needed
Ganglion cysts don’t require treatment unless they press on a nerve, provoke wrist pain, or affect muscle function. You can have it aspirated if a cyst hurts or you don't like its lumpy look. You can get rid of it by getting a quick and painless procedure in which your doctor sticks a needle into the cyst and drains out the fluid.

4. They Feel Firm and Moveable
If you touch a ganglion cyst, it will likely feel firm—not soft or squishy. This is because the fluid inside is thick. Most of the time, the cyst can also be moved around under the skin. It usually has a smooth and rounded shape, making it easy to identify.

5. The Size Can Change Over Time
Ganglion cysts can grow, shrink, or even disappear on their own. Sometimes they fill up with more fluid, making them appear larger. Other times, the fluid leaks out and the cyst gets smaller. It’s not unusual for these changes to happen over weeks or months.

6. They Are Always Non-Cancerous
Ganglion cysts are benign, meaning they are not cancerous and don't become cancerous. Most doctors can recognize them just by examining them. Sometimes an X-ray or ultrasound may be done to rule out other conditions, but these are not always necessary.

7. They Can Come Back
Even if you get a ganglion cyst removed, there’s still a chance it can return. This happens to many people and doesn’t mean anything is wrong. If your cyst comes back, you can discuss other options with your doctor, including repeating the procedure or simply watching it over time.

8. You Can See Through Them With a Light
One way to tell if a bump is a ganglion cyst is to shine a small light—like a flashlight—on it in a dark room. If the light passes through, the lump is likely filled with fluid, which is a sign of a ganglion cyst. Solid masses won’t let light pass through like this.

9. They Used to Be Called “Bible Cysts”
A long time ago, people tried to get rid of ganglion cysts by hitting them with a heavy book, usually a Bible—hence the name “Bible cyst.” This old method is not recommended today. Hitting a cyst can damage the surrounding joint or tendon and doesn’t offer a lasting solution.

10. They Can Appear in Different Areas of the Body
Although ganglion cysts are most common on the wrist—either on the back or front side—they can also develop on the foot, ankle, fingers, or near any joint or tendon. If you’ve had a joint injury in the past, you might be more likely to develop a cyst in that area.