What Causes Numbness And Pain On The Left Side Of My Body?

I have had numbness and pain on the left side of my body. Sometimes i feel like my blood circulation is being cut of or i can feel my blood running through my body. My face hurts sometimes and my left eye is red and irritated. Ive had blood drawn and 2 C.T scans but they came back clear. Some doctors say i have low iron while others cant find anything at all. If you could please help it would be greatly appreciated. Thank you.