Hi doctor , I have been working out or doing Zumba twice a week and on the bicycle for about 3 months. My right knee keeps swelling without pain or with numbing pain and there is tightness in my thigh and calf muscle. When I am not working out knee still swells but does not bother me much when I am working out. When I am home and leg is straight swelling goes down over night, but once up again and start to move knee swells again. There is a difference in the tightness of the muscle on the right leg than on the left leg. I use to be a smoker and quit about 9 months ago, started eating healthier (more green veggies and fruits and plenty of water) cut out over a 3rd of sugar intake. Mother passed with Pancriate cancer, dad had mouth and lung cancer. Diabeties run in family as well as arthritis.