A ganglion is a fluid-filled swelling of the lining of a joint or tendon. Although ganglions can form on any part of the foot, they most often appear on the ankle or the top of the foot. Ganglions tend to change in size and usually grow slowly.

Repeated irritation can weaken the lining of a joint or tendon and lead to ganglion cysts. People who wear boots are more vulnerable to ganglions, as this type of footwear puts stress on the foot and ankle. Bone spurs may also cause ganglions by irritating the joints and tendons.

Ganglions often form with no symptoms. But if the ganglion puts pressure on the nerves in the overlying skin, it can cause tingling, numbness, or pain. Ganglions sometimes swell and their size can change with different activities or a change in weather.

Because ganglions are sometimes mistaken for tumors, it's important to have a complete examination and, possibly, tests to confirm the diagnosis. Your podiatrist will ask you questions such as how long you've had the ganglion cyst, what kind of symptoms you're feeling, if it has changed in size, or if its size varies according to your activities.

During your exam, your podiatrist may do a translumination exam, shining a light through the swelling (usually you can see through a ganglion, but not through a tumor). When your foot is pressed, a ganglion feels spongy and the fluid moves from side to side.

If a bone spur is detected, x-rays may be needed. Fluid removal may be done to help determine the degree of the swelling and to decrease pain. To confirm a ganglion cyst, and MRI may be done, which reveals images of soft tissue and bone. Sometimes, special dyes may be injected into the area to show the outline of a ganglion.

Ganglions are often difficult to treat without surgery, but nonsurgical methods may be helpful in relieving some of your symptoms. Nonsurgical care may include:

If a ganglion is causing ongoing or severe pain, your podiatrist may recommend surgery. The entire ganglion wall is removed during the procedure; some surrounding tissue may also be removed.

After surgery you may feel pain, swelling, numbness, or tingling for several weeks. You'll probably be able to walk soon afterward, though your foot may need to be wrapped or in a cast. Be sure to contact your podiatrist if you notice any problems in the future. Although surgery is usually successful, there is a chance that the ganglion will recur.