Synovial cysts are small, fluid-filled lumps that tend to form on the lower spine. These cysts are not cancerous and often do not cause any symptoms. However, they can sometimes lead to problems such as sciatica.

Treatment options for synovial cysts include taking pain medication and seeking physical therapy. If a cyst is causing severe pain or other debilitating symptoms, a doctor may recommend surgery.

It is important to note that synovial cysts are not the same as ganglion cysts. Ganglion cysts mostly develop near joints and tendons in other parts of the body, not on the spine.

In this article, we discuss what synovial cysts are, as well as their symptoms and causes. We also explore when to see a doctor, diagnosis, and treatment.

What is a synovial cyst?

man with pain in spine that may be caused by a synovial cyst
Synovial cysts may cause pain in the lower part of the spine.

A synovial cyst is fluid-filled sac that most often develops on the lower spine. These cysts are benign, which means that they are not cancerous. Synovial cysts can develop without causing any symptoms.

The synovium is a thin membrane that lines the inner surfaces of joints. This membrane produces synovial fluid, which helps lubricate and protect joints from wear and tear. This fluid can sometimes build up within the membrane to form a synovial cyst.

Synovial cysts can develop around any joint in the body. However, more than 90 percent of synovial cysts affect the facet joints of the lumbar spine. The lumbar spine is the lower portion of the back, where the spine curves inward.

Ganglion cysts are fluid-filled lumps that can develop around joints and tendons in any part of the body, particularly the hand and wrist.

Although ganglion cysts are very similar to synovial cysts, they are slightly different. One key difference is that ganglion cysts do not contain a lining of synovium cells.


Symptoms depend on the size and location of the cyst. Many people with synovial cysts do not experience any symptoms or discomfort.

However, symptoms of a synovial cyst on the spine may include:

  • pain or discomfort in the lower back
  • difficulty walking or standing
  • pain, numbness, or tingling in the legs, such as sciatica


Doctors do not fully understand why synovial cysts develop.

Facet joints sit between each of the spine’s vertebrae and allow it to bend and twist. Synovial cysts develop on the spine when the facet joints degenerate and produce excess synovial fluid.

Synovial cysts are more common in older adults and people with joint conditions such as arthritis. In these people, the facet joints may degenerate at a faster rate, producing synovial cysts.

When to see a doctor

Synovial cysts that do not cause symptoms do not usually require treatment, and a person may not even realize that they have one.

However, people with symptoms that may indicate a synovial cyst, such as recurrent lower back pain and sciatica, should see a doctor.

There are treatments available that can help reduce the symptoms of synovial cyst.


medical technician preparing woman from MRI on spine
Doctors may use an MRI scan to diagnose a synovial cyst.

Doctors will often begin by asking about a person’s symptoms and reviewing their medical history. They may then carry out a physical examination of the back and spine.

If the doctor finds a lump along the person’s spine, they may perform an ultrasound to determine whether it is a synovial cyst.

Other imaging tests a doctor may recommend to help confirm a diagnosis include an MRI scan, a CT scan, or an X-ray. These imaging tests can also help rule out other possible conditions.


Treatment generally depends on the size of the cysts and severity of the symptoms.

Synovial cysts are generally harmless, so treatment is often unnecessary. However, some people may experience pain, difficulty walking, or problems such as sciatica.

For mild symptoms, a doctor may suggest a period of rest and observation. Physical or occupational therapy may also be an option for some people.

A doctor may also recommend taking over-the-counter or prescription medications to help reduce pain and inflammation. This may include the use of nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen.

For more severe symptoms, a doctor may recommend steroid injections, which can help relieve pain and pressure from the cyst.

However, steroid injections can also cause serious side effects, so a doctor will typically limit the number of these a person receives.

If more conservative treatment options are unsuccessful in relieving a person’s symptoms, a doctor may recommend surgery.

The aim of the surgery is to remove the cyst and reduce pressure on the spinal cord and surrounding nerves. There are several surgical options available for treating synovial cysts.


close up of physicians hands holding steroid injection
Steroid injections may help severe symptoms.

Synovial cysts are small, fluid-filled lumps that can form around joints. They usually develop on the facet joints of the lumbar spine and are generally harmless.

Because synovial cysts often do not cause any symptoms, a person may not be aware that they have a cyst. However, the cysts can sometimes put pressure on the spine and surrounding nerves, which can lead to pain and other problems.

People who have unexplained back or leg pain, difficulty walking, or sciatica should see a doctor for an evaluation.

Treatment options for synovial cysts include resting, seeking physical and occupation therapy, and taking pain medications.

For people with more severe symptoms, a doctor may recommend steroid injections or surgical removal of the cyst.