What Causes Fluid Behind The Knee

What Causes Fluid Behind The Knee


Fluid on the knee, also known as water on the knee or knee effusion, means the buildup of excessive fluid around the knee joint, which could have been caused by different health conditions like, overuse injuries, infection, diseases and traumatic injuries. Fluid on the knee can cause pain, stiffness and swelling, making it difficult for you to take part in daily activities.

What can cause fluid on the knee?

What Causes Fluid Behind The Knee

There are a variety of ways that fluid can begin to accumulate in the knee joint. Injuries such as broken bones, ligament or meniscus tears, or simple overuse have been known to cause an excess build-up of fluid around the knee joint.

There can be the accumulation of fluid on the knee through rheumatoid arthritis or osteoarthritis. There can be extra production of synovial fluid in the knee through arthritis.

Infection in the knee joint; the fluid on the knee is pus, and not synovial fluid.

There can be the accumulation of fluid on the knee after an accident. In most cases, the fluid is blood which can be through a fracture caused to the knee. The swelling of the knee often takes place within some minutes of the injury occurring.

Gout and pseudo-gout can also cause fluid on the knee. Uric acid crystals can accumulate in the knee through gout, leading to the knee joint’s inflammation and swelling, while there also could be the formation of calcium crystals in the knee through pseudo-gout.