As long as I can remeber as a kid I get this weak spell to where I get really weak and need to rest for awhile I have found that eating something helps alot, and goes away in about 10 min. I have checked my sugar while I was having one and it was normal. I am 31 now and getting more worried with it every time I get a weak spell. I have mentioned it to doctors but to some its just come back to see what happens. But I dont because of the lack of missing work or dont have alot of money to do any thing about.