Yes, quite often it is possible to have fluid on the knee with no pain. There are a number of reasons how and why this occurs, so let’s look at them in more detail.
Quite a lot of patients see us and they actually don’t have pain, but they do have swelling. This can be due to benign causes of knee swelling, or it may be they have swelling without inflammation. The position of the swelling is important, and some pockets of swelling might be extra-articular, so they are outside the actually knee joint and closer to the skin, causing less pain and pressure.
Types of Fluid Accumulation
Synovial Fluid Increase
Synovial fluid is a natural lubricant for the knee joint, but its excessive accumulation can lead to an effusion. This type of fluid buildup can occur due to various reasons, including minor injuries and chronic conditions.
Blood Accumulation (Hemarthrosis)
In some cases, blood can accumulate in the knee joint, a condition known as hemarthrosis. This can happen after an injury such as an anterior cruciate ligament (ACL) tear, and this is going to be very painful.
Other Types of Fluid Buildup
Other fluids, such as pus from an infection or fluid from a ruptured cyst, can also accumulate in the knee joint. Conditions like bursitis, where the bursae (small fluid-filled sacs that cushion the knee bones) become inflamed, and this can be painful too.
Characteristics of Painless Knee Effusion
Visual Appearance of the Swollen Knee
A swollen knee with no sign of pain can still be quite noticeable. The knee may appear larger than normal, with a visible bulge or puffiness. This water balloon-like appearance is due to the fluid accumulation within the joint.
Range of Motion Changes
Even without pain, the range of motion in the knee can be affected. Patients may find it difficult to fully bend or straighten the knee due to inflammation. Sometimes the pain only occurs at end of range flexion or extension.
Perception of pain
Different people might perceive pain differently. For example, pain to one person could simply be stiffness to another person. Our perception is important here. Also, everybody reacts differently to the pain triggers, with some people being more sensitised, and others being able to block it out more easily.
When to Seek Medical Attention Despite Lack of Pain
Even without pain, it’s essential to consult a healthcare provider if you notice persistent knee swelling. A doctor or physiotherapist can provide professional advice and perform necessary tests to prevent potential complications. Regular check-ups are essential. These visits can help detect any changes in the condition early and allow for timely intervention.