PLEASE DONT hit it with a book.
The old name for a ganglion is a bible cyst, from the practice of bursting it with a heavy volume, and it is a genuinely bad idea — it can bruise the tissue underneath, and the cyst usually refills anyway.
Popping one at home with a needle is worse, because you are putting a hole into a sac that connects directly to a joint or a tendon sheath.
Most ganglions need nothing at all.
The useful question is whether yours is causing a problem, and the answer for most people is no.
What it actually is
A sac of thick joint fluid that has pushed out through a weak point in a joint capsule or tendon sheath, most often on the back of the wrist. It is not a tumor and it is not sinister. It changes size because fluid moves in and out of it, which is why it swells after a heavy day and shrinks after rest.
A meaningful proportion resolve on their own given a year or two.
When to just leave it
- It does not hurt
- It does not limit movement
- It changes size over weeks or months — a reassuring feature, because it confirms it is fluid
- It sits on the back of the wrist and bothers you only when you look at it
Cosmetic dislike is a legitimate reason to want it gone. It is worth knowing that the treatments carry recurrence rates and small risks, so the trade is real rather than obvious.
When it is worth doing something
- It hurts, particularly at end of range — pushing up from a chair, press-ups, weight through the hand
- It restricts movement
- It presses on a nerve. A ganglion in the palm near the wrist can compress the ulnar nerve and cause numbness in the ring and little fingers — see Guyon’s canal syndrome
- It is a hard little seed in the palm at the base of a finger, painful to grip anything. Small and disproportionately painful — see seed ganglions
- It is at the last joint of a finger and there is a groove down the nail. That is a mucous cyst, which behaves differently, is associated with arthritis in that joint, and should not be punctured because of infection risk near the joint
A lump that changes size is usually fluid. A lump that never changes size at all is the one to get looked at.
The real options
- Watch it. Reasonable, free, and sufficient for most
- Aspiration. Drawing the fluid out with a needle, done properly, in clean conditions. Quick, but a substantial proportion recur because the stalk connecting it to the joint is still there
- Surgical excision. Removes the sac and its stalk. Lower recurrence than aspiration, but not zero — which is the thing people are least prepared for. See ganglion excision recovery
- A splint, occasionally useful to reduce a painful one by limiting the end-range positions that pump fluid into it. Short term only
Get it assessed rather than ignored if
- It is hard and has never changed size
- It is growing steadily rather than fluctuating
- The skin over it is red or hot
- There is numbness, tingling or weakness in the hand
- It appeared after an injury
- It is not in a typical ganglion location
A hard lump that never changes is more likely something else. On the back of the wrist that may be a carpal boss, which is bone. Elsewhere it may be a giant cell tumour of the tendon sheath — benign, despite the name, but it needs identifying rather than assuming.
The full picture on the commonest type is in wrist ganglion cysts.
Most ganglions are a lump you notice, not a problem you have.
Every article on this site is written using the Closing Window Method: name the window your condition runs on, find where you are in it, and act while it’s still open.