They're also known as "Palpitations" - I get em all the time, and contrary to common belief its not due to too much weight.
They can be caused from too much caffine, not enough sleep, MSG and other food additives etc. Its always best to get them checked out just in case. I had an attack for 18 hours once. I find I get them when I have tummy "wind" and also when I get pissed off or nervous.
Supposedly they are common in early twenties females. (I've done my research!!) And Now i'm on beta blockers to regulate my heart beat. fun fun fun
