What Causes Swelling In The Ankle While Looking For Treatment For A Bakers Cyst Behind My Right Knee?

I have no history of high blood pressure...however just last week developed a bakers cyst behind my right knee. I had an ultra sound on my left leg to rule out any blood clots, however yesterday into today my left ankle/foot are quite swollen and I m not sure if this is also associated with the cyst. I am 60 yrs old, female, type 2 diabetic with and A1C reading of 7.1