I've Been Having Slight Knee Pain. Mild Throbbing And Aching.

I've been having slight knee pain. Mild throbbing and aching. when I sleep and place the knee over the other knee it has more pain. I have been going to fitness classes and probably caused or aggravated this. Could this be a slight meniscus tear or something else. 64, healthy, and very active women. Should I consult with an orthopedic specialist.