What you describe sounds like palpitations. Occassional palpitations are normal, everyone has them. Frequent palpitations, we look for underlying causes. Serious heart conditions are relatively rare in your age group if you have no history of them. Possible causes: Look first at the amount of stimulants in you diet. Caffeine is a biggie. Coffee, Mt. Dew, Colas, energy drinks all have caffeine or caffeine-like substances. Over the counter diet pills are also known to give people palpitations. If you cut-out any or all of these in your diet, your palpitations will probably go away. If you are still having them after several days off these substances, see your doctor.