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Baker’s Cyst

Baker cysts are small lumps filled with fluids that form behind the knee. They develop following damage to the knee joint or swelling around it. Although cysts are not serious, it is still important to see a doctor for diagnosis. The symptoms of Baker cysts may be similar to those of more severe conditions such as blood clots.

By Able Health I Medically reviewed by Dr. Alireza Estedlal

Page last reviewed: February 2024 I Next review due: February 2026

What is a Baker cyst?

A Baker cyst, also known as a popliteal cyst or synovial cyst, is a small, fluid-filled growth forming behind the knee. The cyst occurs when damage to the knee joint or tissues surrounding it causes excess fluid to drain out. These fluids only drain in a single direction at the back of the joint, and this accumulation creates a sac that develops into a Baker cyst.

Typically, Baker cysts are benign lumps, meaning they are not tumors and do not indicate or cause cancer.

If you notice any new lump or growth at the back of your knee, particularly after a recent knee injury or if you have arthritis, it is important to see a doctor for assessment.

Symptoms of Baker Cyst

The most noticeable Baker cyst symptom is the bump at the back of the knee. Additional common symptoms are:

  • Pain in the knee
  • Stiffness
  • Difficulty bending the knee fully as usual (limited motion range)
  • Swelling in the knee or the leg surrounding it

Some individuals with Baker cyst may not have any symptoms. Moreover, one might not be aware that they have the growth till the physician recognizes it while detecting other conditions or problems affecting the knee.

In other cases, Baker cysts can result in discoloration and swelling of the lower leg, a symptom similar to a blood clot. Blood clotting is a medical emergency; hence, you should immediately seek medical care if you suspect the problem. The practitioner will check the symptoms to identify whether it is a Baker cyst or a blood clot.

Cause of Baker Cysts

Baker cysts develop due to swelling from damage to the knee joint. The prevalent causes include various forms of arthritis and knee injuries.

The most common types of arthritis triggering Baker cysts are:

  • Osteoarthritis
  • Rheumatoid arthritis
  • Gout

For people with a knee injury, the damage could lead to swelling that causes Baker cyst. The knee injuries causing Baker cysts include:

  • Repetitive strain injuries (overuse injuries)
  • Hyperextensions
  • Meniscus tears
  • Sprains
  • Bone fractures
  • Dislocations

Injuries damaging the ligaments of the knee can result in Baker cysts such as:

  • ACL tears
  • MCL tears
  • LCL tears
  • PCL tears

What are the risk factors of Baker cysts?

Baker cysts can develop in anyone, particularly individuals who have arthritis or have experienced a knee injury. However, certain groups of people have increased risks of developing Baker cysts. They include:

  • Persons aged between 35 and 70
  • Athletes
  • Individuals who put too much pressure on their knees when working or during hobbies
  • People with arthritis

What are the complications of Baker cysts?

One of the most prevalent complications of a Baker cyst is rupturing or breaking. A rupture occurs when the cyst's sac fills with fluid too quickly or is under a lot of pressure, causing it to burst. This is similar to filling a water balloon too fast, wherefluid pours into a tiny elastic container with excess pressure, making it pop.

  • A ruptured Baker cyst could result in various symptoms in the knee and lower leg, such as:
  • A sharp, stabbing pain in the knee or calf
  • Swelling in the calf and lower leg
  • A sensation of water running down the leg (inside the body)
  • Nerve damage
  • Compartment syndrome (painful pressure build-up in the muscles)

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Baker’s Cysts Diagnosis

A Baker cystis diagnosed through a physical examination, which involvesassessing the leg and checking for a lump behind the knee. Your medical provider will ask about the onset of the bump and any other symptoms you are experiencing. If you have had a knee injury, it’s important to clarify what transpired.

Diagnostic tests for Baker cysts

Your medical doctor may use these imaging tests for Baker cyst diagnosis:

  • X-rays
  • Ultrasound
  • Magnetic resonance imaging (MRI)

Management and Treatment

Baker cyst treatment options

The treatment mainly focuses on addressing the underlying cause of the Baker cyst instead of the cyst itself. Usually, the cyst resolves once the knee damage causing the condition is treated.

Medical doctors will recommend treatment depending on the type of injury or problem you have. The available options include:

RICE method

The majority of minor injuries may be addressed using the RICE technique:

  • Rest: Avoid activities that led to the injury to prevent further damage.
  • Ice: Use an ice pack or cold compress for at least 10 to 15 minutes per hour in the first 24 hours following the injury. After that, start applying ice every 3 to 4 hours. Do not put the ice pack directly on the skin; instead, wrap it in a washcloth or towel.
  • Compression: This method helps minimize the flow of blood to the affected, hence lessening swelling. You can use a compression bandage, wrap around the knee, or put on compression pants to assist in pressure maintenance on the knee.
  • Elevation: When necessary, you can raise your knee and lower leg over your heart level and use pillows, cushions, or blankets for support.


The medical provider may recommend medications to help relieve pain and ease swelling.

In most cases, people can opt for over-the-counter NSAIDs like aspirin, ibuprofen, and naproxen, or acetaminophen (Tylenol®). However, it’s not advisable to take these drugs for overten days without consulting your doctor.

They may also recommend prescription corticosteroids or cortisone shots.

Physical therapy

For those recuperating from an injury or have arthritis, the doctor can recommend physical therapy. A physical therapist can guide you through stretches and exercises to help strengthen the muscles surrounding the damaged knee.

Knee surgery

Surgery may be necessary to address torn cartilage or ligaments in the knee or if you have a fractured bone. In rare cases, surgery may be required to drain or remove a Baker cyst, particularly if it causes severe pain or hinders normal knee function. Your surgeon will explain the form of surgery needed for your condition and what you should expect during the recovery process.


The most appropriate way of preventing a Baker cyst is to avoid knee injuries. These tips will thus help you stay safe during sports or any other physical activity:

  • Wear proper preventive gear.
  • Avoid ‘playing through pain’ if you experience knee pain during or after physical exercise or activity.
  • Allow time for resting and recovery, especially after rigorous activities.
  • Always stretch and warm up before you start working out or playing sports.
  • Stretch and cool down after a physical activity.

To lower the risk of knee injury, consider the following general safety measures:

  • Ensure your house and workplace are clutter-free to avoid tripping.
  • Use the right tools at home while reaching for items. Do not stand on countertops, chairs, or tables.
  • If you have trouble walking or are at a higher risk of falls, you should use a walker or a cane.


How long does a Baker cyst last?

The period a Baker cyst lasts is based on the underlying cause. Many cases of Baker cysts resolve once the swelling reduces and the knees begin to recover, typically in a few weeks.

What happens if Baker's cyst is left untreated?

A Baker cyst can sometimes disappear on its own. However, it is essential to see a medical doctor immediately if you notice new growths or lumps on the body. For cases where treatment is not required, diagnosis is still necessary to ensure that it’s not a serious problem.

As the knee recovers, the fluid in the cyst will be reabsorbed into the body. You should also follow the doctor’s advice to aid recovery and avoid further damage.

Living With

When should I visit my medical provider?

You should see your doctor immediately if you notice any lump on your leg. It’s crucial to get a diagnosis to determine whether it’s a Baker cyst or a more serious issue like a blood clot.

When should I go to the ER?

Go to the ER if you experience trauma or suspect a broken bone or knee dislocation. Do not try to realign a joint by yourself. Also, keep the knee still as you can and seek immediate medical attention.

Questions to ask your healthcare provider

  • Do I have a Baker cyst or another problem?
  • What initiated the cyst?
  • Which treatments will I require?
  • Is surgery necessary?
  • How long will the cyst last?

How do I sleep with a Baker cyst?

Having a Baker cyst does not interfere with your sleep. So even if you lie on your back, you will still sleep normally. The pressure from lying down is unlikely to cause the cyst to rupture. However, if applying pressure behind the knee on or around the cysts causes pain or discomfort, see your medical provider.