I Have Been Experiencing Vision Problems And Recently Had To

I have been experiencing vision problems and recently had to have bifocals, which have not helped very much. Also experiencing fatigue and weight loss. Recently symptoms of upper leg pain, upper back pain and once in awhile a little numbness in small finger on left hand. I do experience at my age hot flashes, but now when I have one it feels like I'm being stuck with pins around my neck area mostly. What could all this be a sign of or is it more than one particular thing?