What Might Cause Pain Behind the Knee?

Sometimes pain behind the knee is due to a Baker’s cyst. This is when extra fluid builds up in the knee and forms a small balloon-like sac behind it. Baker’s cysts can happen because of arthritis, a small tear in the knee’s cartilage, or other knee injuries. When the knee becomes irritated or inflamed, extra fluid is produced, and it may collect in the back of the knee, causing swelling and discomfort. Apart from a Baker’s cyst, other causes may include injuries to tendons, ligaments (which help hold the knee in place), or even a strain in the muscles like the hamstrings. Nerve problems, such as irritation of the saphenous nerve (which mainly causes pain along the inside of the knee), may sometimes contribute to pain that feels like it is coming from behind the knee. In general, it is important to have persistent or worsening pain checked by a doctor, so the exact cause can be identified and treated properly.