Also if you are consuming excess amounts of caffeine.It causes heart problems.see a cardiologist to get a diagnoses.it might be an arrhythmia or even worse a murmur. I had a temporary heart murmur when I was drinking a lot of Mt.Dew.They can be dangerous. Thank GOD it went away.if you take caffeine with meds containing affedrine can cause your heart to race because they both stimulate you.cold meds and caffeine don't mix well. see ur doc.
The reason your heart beats very fast when you are not even moving around could be caused by anemia, dehydration, thyroid disorders, low blood pressure, fever, infections in the lungs, heart disorders and many more. A normal heart beat ranges from 60 to 100 beats per minute.