Forearm circulation problem

I have recently developed a strange pressure in my forearms - it feels as though my forearms are swollen and they are slightly painful. They are most comfortable if my arms are hanging down. I noticed my right forearm was developing a sensation of pins and needles when I did cardio vascular exercises at the gym and I would have to lower my arm to make it feel better. This has been happening for about a month. Now the problem is in both arms and it is more constant. It has only been like this for a couple of days. Should I be concerned? Why should this be happening? I would be very grateful if you could give me some idea of what I should do.