What Causes Feeling Of Electric Shock All Over The Body?

Dear Sir I am experiencing very strange feelings all over my body, like electric shocks under my skin - mylegs, my body, my face, the soles of my feet itch, my palms do also, I have this also deep inside me, and the degree varies - sometimes I feel light headed, my limbs feel heavy, this is at night when I lay down - and also i can hear my blood thumping around my body! Have had various tests, seen various consultants..... waiting for some more blood results.... Help please?? Thank you.