Bakers Cyst
Overview
A Baker cyst is a small, fluid-filled sac that forms behind the knee. It often creates a noticeable bulge and a feeling of tightness. Sometimes called a popliteal cyst, this bulge might be accompanied by pain. The pain can worsen with activities that put stress on the knee, like bending or straightening it fully.
Most often, a Baker cyst is a sign of a problem within the knee joint itself. This could include conditions like arthritis, where the joint becomes inflamed, or a tear in the cartilage, which cushions the joint. These issues can cause the knee to produce more fluid than usual. While the cyst itself can be noticeable and uncomfortable, addressing the underlying cause of the extra fluid is typically the best way to find relief.
Symptoms
Baker cysts are fluid-filled sacs that can develop behind the knee. Sometimes, these cysts don't cause any problems at all, and you might not even know you have one. However, if you do experience symptoms, they often include swelling, either directly behind the knee or extending down the leg. You might also feel knee pain, or find it harder to bend your knee fully (stiffness). These symptoms are sometimes more noticeable after you've been moving around a lot or standing for a while.
If you notice swelling and pain behind your knee, it's important to see a doctor. While rare, these symptoms could also be a sign of a blood clot in your leg. A doctor can properly diagnose the problem and recommend the best course of action.
When to see a doctor
If you have pain and swelling behind your knee, see a doctor right away. While it's not very common, this could be a sign of a blood clot in a vein in your leg. A blood clot, or deep vein thrombosis (DVT), can sometimes cause swelling and discomfort in the back of the knee. It's important to get checked out by a healthcare professional to determine the cause of the pain and swelling and to rule out any potential serious conditions.
Causes
Synovial fluid is a special liquid that helps your knee move smoothly, like oil in a machine. It reduces the rubbing between the parts of your knee joint. Sometimes, your body makes too much of this fluid. This extra fluid can collect in the back of the knee, forming a swelling called a Baker cyst.
Several things can cause this extra fluid buildup and a Baker cyst. One common cause is inflammation in the knee joint. This inflammation can be linked to different types of arthritis, where the joint lining gets irritated. Another reason is a knee injury, like a tear in the cartilage that cushions the joint. This injury can also lead to extra fluid production.
Complications
Baker's cysts are fluid-filled sacs that sometimes form behind the knee. They're usually not a serious problem. However, in rare cases, a Baker's cyst can burst. When this happens, the fluid inside, called synovial fluid, can leak into the calf muscle. This can cause a number of symptoms.
A burst Baker's cyst often leads to sharp, intense pain in the knee. The area around the knee, and especially the calf, will swell up. Sometimes, the skin of the calf may become red or inflamed, or you might feel a sensation like water running down the calf. These symptoms are a sign that the synovial fluid has leaked into the calf.
Disclaimer: August is a health information platform and its responses don't constitute medical advise. Always consult with a licenced medical professional near you before making any changes.