Flexor Tendon Sheath Ganglion Info
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A benign, fluid-filled cyst arising from the flexor tendon sheath – often painless, but can cause clicking or limited finger movement.
What you're feeling
You may notice a lump on your hand or wrist that feels firm or soft. This bump often grows slowly over time. About 40% of these wrist lumps get smaller on their own within the first 6 years. However, many people feel pain or discomfort as the cyst presses on nearby structures. You might notice the area hurts more when you use your wrist for forceful tasks.
Daily activities can become difficult if the lump gets in the way. Simple motions like reaching behind your back to fasten a bra or tucking in a shirt may feel awkward or painful. If you sleep on your side, the pressure on the wrist can cause a flare-up of pain at night. Some patients report that symptoms are worse upon waking in the morning.
If the cyst presses on a nerve, you might feel weakness or a loss of muscle bulk in the arm. In rare cases, this pressure can cause numbness or tingling. Your surgeon will check if the pain comes from the cyst itself or if it is affecting your movement. While many cases resolve without surgery, persistent pain or limited motion often leads to a discussion about treatment options.
What's actually happening
A ganglion cyst is a fluid-filled sac that forms near your joints or tendon sheaths. Think of your joint capsule as a protective sleeve around the joint. Sometimes, this sleeve develops a small leak or weak spot. Fluid from inside the joint escapes through this opening and collects in a balloon-like pouch nearby. This is why you might feel a lump that changes size or becomes painful when you move your hand or wrist.
These cysts can press on nearby structures, causing specific problems. If the cyst sits inside a nerve, it can squeeze the nerve and cause weakness or numbness. In rare cases, a cyst can even get trapped inside a nerve itself. If it forms near a tendon, it might act like a knot in a rope, causing your finger to catch or lock. Sometimes, the cyst grows large enough to block joint movement entirely, making your knee feel stuck or your elbow hard to straighten.
The fluid inside often comes from the joint itself, which supports the idea that these cysts are connected to the joint lining. While many cysts shrink on their own over time, some persist or grow. About 40% of wrist ganglion lesions decrease in size over the first 6 years after you see a hand surgeon. However, most cysts return after being drained with a needle. This is why your surgeon might discuss other options if the cyst is painful or limits your movement.
What we can do about it
Many ganglions on your wrist or hand will shrink on their own. About 40% of these cysts decrease in size over the first 6 years after you see a hand surgeon. If you have a child, a cyst often resolves within 18 months. Your surgeon may suggest watching the lump closely or using simple pain relief while you wait. Physiotherapy can help manage stiffness, but it does not remove the cyst itself.
If the lump causes pain, your surgeon might try a needle to drain the fluid. This is called aspiration or puncture. It is a low-cost option with no downtime and a low chance of the cyst coming back. Some patients need a second puncture, and studies show no recurrences after this second attempt. For wrist ganglions, aspiration is often the first step. However, most ganglions do return after a single aspiration. You should not use chemical injections (sclerosants) to treat these cysts, as they can cause serious injury to nearby blood vessels.
Surgery is considered when the cyst remains painful or keeps coming back after trying drainage. Your surgeon can remove the cyst through a small cut or using a tiny camera called arthroscopy. Open surgery has a lower chance of the ganglion returning compared to needle drainage, with about a 10% recurrence rate. Arthroscopic surgery also allows your surgeon to treat other problems in the joint at the same time. This option is effective for cysts inside the knee or those pressing on a nerve, often restoring full strength and movement.
When to see someone
See your GP if you have a lump that causes persistent pain, weakness, or locking in your wrist or finger. Ask for a specialist review if symptoms interfere with sleep or work, or if the lump suddenly worsens. About 40% of wrist ganglions shrink over the first 6 years, but most return after needle drainage. In children, cysts often resolve within 18 months. If you have nerve symptoms like numbness or muscle weakness, seek help quickly. Your surgeon can check if the lump is pressing on a nerve or joint.
