What you described (fast heart beat, light headed, weird feeling throughout the body, about to faint, feeling that you're about to die) are ALL symptoms of an anxiety/panic disorder.

You may not realize that you are stressed out but you probably are. Nothing is wrong with you - you are just stressed out in some way. It can be anything... you need to sit down and try to figure out what your 'stressors' are. Are you handling every situation that comes your way just fine? Or do you have some problems? How is your social life? Do you go out often or do you stay in? If you stay in, then you need to start going out and breathing fresh air and walking a lot. You need to also be very social.

If you find that you DO have an anxiety problem, then post again and we'll try to suggest how you can calm your anxiety down. Please don't read too much into anxiety and panic disorders because reading about them could actually make your symptoms worse if you are suffering from those disorders.

Always check any possibility of physical illness. One of the most common causes of a reaction like this, especially in someone around your age up to 18, are blood sugar issues. If there is a history of diabetes in either side of your family, chances are you could be developing some sort of a problem and this is the first warning sign of it. Regardless of what people say, you know when you're stressed because you can feel it, your body just doesn't suddenly do something like that because you're stressed. Suddenly reactions like that where you're sure you weren't stressed out or anything are physical, something is going on. Has this ever happened before? The light headed feeling is a dead give away that likely you are starting to get a blood sugar problem. Catch it now and be sure if you have it or not and you can easily correct it. Do you have any other symptoms through the day? Sleepiness that seems odd, odd fainting spells, confusion, anything? When I was your age I had the same thing happen to me, only to find out years later, and after getting a horde of symptoms you don't want to experience, that it was simply a blood sugar problem easily corrected with the proper diet.

I agree with Stan to check out the physical before the emotional. If you have never had an anxiety attack before then you may have just not eaten enough that day. Every person will have symptoms like that if they don't eat enough of the right kind of foods. Try eating many small meals a day and nibble on things periodically through the day. Avoid sweets and caffeine! Both are problematic for hypoglycemics. If you eat well and still have these feelings then you need to consider some cognitive behavioral therapy. I would avoid any kind of medication until you are a little older, maybe in your twenties.

Hope you feel better,
OE