-- Posted by SheIsLegendx at 3:42 pm on July 10, 2008 Number one; I have NO IDEA where to post this. Second; What could cause random blackouts in a health 18 year old boy? It's been happening so often to him. Someone help me. -- Posted by Porcelina at 11:55 pm on July 10, 2008 Really, your friend needs to see a doctor and have tests run. There are so many multitudes of things that could be wrong. I mean, it could be anything from a mere vitamin deficiency to something very, very serious. My friend's sister kept randomly becoming nauseous and then blacking out whenever she was in a bit of a crowd, turned out she was having tiny strokes.