Hi my name is Christina. recently I have been having these weird attacks. I will be standing still and all of a sudden my heart begins racing, it feels like I have been running 5 miles really fast. Then I cannot breathe or catch my breath and I start feeling like I am about to black out. These last for normally 2-3 minutes and I have to sit down. The last time was last night. I am 18 and wondering what is going on.
Hello, I would explain that your symptoms could be related to postural hypotension or tachycardia.  Another possible cause to consider would be anemia. For this reason, I would recommend checking first your complete blood count.  If anemia is excluded, I would recommend performing a Head-Up Tilt test to investigate for orthostatic intolerance.  Hope I have answered your query. Let me know if I can assist you further.