A ganglion cyst is a noncancerous lump filled with a jelly-like fluid. These cysts are generally harmless, though they can be uncomfortable, particularly when they form on the foot.
Ganglion cysts develop near joints or tendons, often around the wrist, but sometimes on the ankle, foot, or elsewhere on the body.
These cysts tend to disappear on their own, but if a cyst is uncomfortable or painful, a doctor can provide treatment.
Below, learn about the causes of ganglion cysts, what the treatment entails, and more.
A ganglion cyst is a smooth lump that forms near a joint or tendon.
The size may range from that of a pea to a golf ball. The cyst may appear round and be soft or very hard.
Beneath the skin, a ganglion cyst looks like a balloon on a stalk, and it may move freely beneath the skin if a person pushes it.
A person with a ganglion cyst on their foot may have:
- a noticeable lump
- a tingling or burning sensation if the cyst is touching a nerve
- pain, possibly a dull ache, if the cyst is pressing against a joint or tendon
- irritation when wearing shoes, depending on the location of the cyst
The average width of a ganglion cyst on the foot is 2.7 centimeters, or 1.06 inches. When they form on the feet, these cysts cause pain in 67.9% of cases.
Doctors are unsure of the exact underlying causes, but these cysts tend to form in areas of trauma, possibly due to a single event or repeated injuries.
These cysts seem to form when synovial fluid leaks from a joint or tendon and collects in a sac beneath the skin. Synovial fluid cushions and lubricates joints and tendons during movement.
If a ganglion cyst is not causing pain or discomfort, the doctor may simply monitor it for changes.
A doctor typically only offers treatment if a cyst is causing pain or mobility issues. In this case, they may recommend:
Aspiration and injection
Aspiration involves draining the cyst of its fluid. The doctor may then inject the cyst with a steroid medication.
More than one session may be necessary, and the cyst may eventually return.
If aspiration and injection is ineffective or inappropriate, the doctor may recommend a procedure to remove the cyst and part of the attached joint capsule or tendon sheath.
However, even after surgery, the ganglion cyst may return.
To ease any pain that a ganglion cyst causes, a person might try:
- putting ice inside a clean cloth and placing it on the cyst, which also helps ease inflammation
- limiting movements or activities while waiting for a doctor’s appointment
- taking over-the-counter pain relief medications
If possible, wear shoes that do not irritate the area. Padding may also help ease rubbing and pressure.
What not to do
A traditional home remedy involves hitting a ganglion cyst with a heavy object, usually a book. This is not only ineffective — it can also damage surrounding tissues.
Never try to pop or drain a ganglion cyst at home. Any attempt could lead to infections or other complications.
Consult a doctor if any ganglion cyst is causing pain or discomfort — especially if it is limiting mobility. A person may also ask about treatment for cosmetic reasons.
A doctor who suspects that a lump on the foot is a ganglion cyst may ask:
- if there are any additional symptoms
- how long the lump has been there
- if the lump has changed size or shape
- about the person’s medical history
They may apply pressure to the cyst to check for tenderness. The doctor may also use a small flashlight to see whether light passes through the lump. If it does, this can help them diagnose a ganglion cyst.
The doctor may also take some fluid from the cyst for testing.
Ganglion cysts are benign lumps filled with a jelly-like fluid. They may disappear without treatment.
These cysts form near joints or tendons, and they can cause discomfort, particularly when they develop on the foot or ankle.
If a ganglion cyst causes any pain, discomfort, or limitation of movement, a doctor may recommend a procedure to drain or remove the cyst. However, these cysts can return, even with treatment.
Never try to pop, drain, or remove a ganglion cyst at home.