I'm 21 years old, and I get dizzy when I stand up and when going up stairs. Sometimes I even blackout, it never lasts longer than a minute though. I have already been to a cardiologist and he says everything is fine with my heart. But at my family doctor I had an ECG? done or whatever and she said it was abnormal. Anywayz, I'm also really tired ALL day everyday. I have started taking 5 hour energy drinks twice a day. They work for a little bit but not long. Can you help?