A guy at church went through this 6 times before the docs figured it out. It was what he called 'tiny strokes'. He was about 35. They were able to treat him in a preventive way but he said the Dr. Said it was only a matter of time before he would have a bigger one. He ended up having one at age 52 but with the medicines taken for all those years, (mainly aspirin I think) when it did hit, it took him out of work for a while but it didn't permantly disable him in any real way.
Signs of fainting can by caused by many things, but maybe you should have a c-scan or something to rule out any blockage in your veins.