What Causes Fluid on the Knee Symptoms and Treatment Reviews

Many people have asked this question before. Today, I want to tackle this question once and for all and help the people who are wondering what causes fluid on the knee.

My main focus will be on the causes, symptoms, and also fluid on the knee treatment. Let me start by saying that I am well aware most of us have experienced a painful knee. That’s not quite like a case of fluid on the knee. However, it could be a symptom of the same.

What is Fluid on the Knee?

Fluid on the knee is a form of knee swelling that’s often as a result of fluid retention around the knee. Fluid in the knee is sometimes referred to as “water on the knee.”  However, the medical term for it should be knee effusion.

What Effects Does Fluid on the Knee Have?

Since it results in knee inflammation of swelling, fluid on a knee joint may easily limit knee flexibility and also the functionality.

For instance, you may find it difficult to even bend or straighten your leg fully or completely. Indeed research has it that a swollen knee joint may only bend 15 to 25 degrees while your leg is at rest.

In addition to that, fluid on the knee might also leave you with severe pain. If left unattended, fluids that accumulate around your knee cap will cause pain. Eventually, you will be unable to settle due to the discomfort.

In the worst-case scenario, fluid retention around the knee will even prevent you from having a good night sleep.

What Causes Fluid Build Up In The Knee?

I have learned that there are numerous causes of knee effusion. And depending on the main underlying condition knee effusion might exhibit different types of symptoms including change or skin color around the knee and pain.

Nonetheless, the main conditions that I have learned of include the following conditions.

Injury to the Knee

Injury to the knee causes trauma. The trauma might be sustained on the knee’s bones, its ligaments, tendons, meniscus, bursae, or even in the articular cartilage. When this happens, it will lead to pain and swelling.

A serious injury such as a tear in the articular cartilage can cause blood flooding the knee joint. This will ultimately lead to significant swelling, burning sensation, stiffness, and possibly bruising too.

Such a condition is usually called “haemarthrosis” and is one of the major causes of knee effusion.

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There are two types of bursitis namely Septic and Non-Septic. All over your body are tiny, thin, fluid-filled sacs. These sacs are called bursa. The bursa protects the joints. However, when a bursa swells, it fills up with excess fluid.

This excess fluid will cause swelling and water retention around the joins such as the knee joints. The swollen knee will often feel “squishy” and but might not be painful. Prepatellar bursitis and pes an-serine bursitis are the most common forms of knee bursitis.

An infected bursa often becomes inflamed and will fill with pus. In addition to that, the swelling knee will appear red and could feel hot.

Knee Osteoarthritis

Knee Osteoarthritis refers to the degeneration of the knees cartilage. When this happens it results in an eventual overproduction of knee joint fluid. This, in turn, leads to water retention around the knee which will cause the knee to swell and become extremely painful.


Gout is a painful accumulation of the microscopic uric acid crystals. It often affects the joints and could leave you with a swollen knee and so much discomfort. If the knee is affected by gout, it could swell pretty fast and possibly come with so much pain, redness, and warmth.


Here are a few things you should remember about chronic swelling on the knee due to fluid buildup.

Does Removing the Fluid Help?

Yes. Removing some of the water or fluid from your knee will easily help to reduce pain and stiffness that is often associated with this condition.

What is the Fluid on the Knee Symptoms?

The fluid on the knee symptoms includes the skin around your kneecap becoming puffy, the knee stiffens, the knee pains and bears weight, redness, and warmth.

What is the Worst that Can Happen with a Swollen Knee?

Chronic swelling on the knee if unattended to can lead to cartilage degradation, joint damage, or bone softening.


Now that you know what causes fluid build up in the knee. I suggest that you take the necessary precautions before the condition gets worse. Talk to your doctor and let them run the recommended tests. From here you should be able to address the underlying cause of fluid buildup.

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