Yes, I have been to the doctors and the have taken some blood tests. Nothing was found in the tests and they cannot figure out what is causing this. All I know is that my blood pressure may get low during exercise. I am planning to test my blood pressure frequently from now on. I would still appreciate if someone would elaborate if they have had the same problem.
Thanks for the suggestion tip8558, but I have tried different diets, it didn't help. I still get dizzy and vomit.
Have you seen a doctor about this, might be something medically wrong. If you have, or do not want to, I suggest doing light exercise and building up. Try yoga or running short distances, maybe a few times around the block.
My 22 year old son does that sometimes. This helped him a lot. http://www.livestrong.com/article/504398-how-to-avoid-puking-after-running/