question: I am a 20 year old female who use to be very athletic. I started getting sharp pains and what seemed like a fluid build up around the knee area so I had to cut way back on the sports. It s almost been a year now that I have noticed the lymph nodes on my upper & lower back, neck, armpit and calf area are swollen and sometimes very painful. (The worst being the ones under my shoulder blades.) What could be causing this? My cousin had lymphoma cancer and my mom has had breast cancer twice. Are these things I should be worrying about?