I Have Had About 7 "spells" In The Past 2

I have had about 7 "spells" in the past 2 months where I suddenly lose my peripheral vision, then my lips go numb..my arms and legs feel heavy and a couple of times it is followed by a severe headache..i cannot pinpoint what causes it because I never am doing the same thing..i had complete bloodwork done a few days before these started and everything was normal..i have been checked twice during these spells by fire dept. and all vitals are normal,it is a very scary feeling, any suggestions?