Im a healthy 19 year old female. I have a varying heart and pulse rate at rest. Sometimes my heart rate is as low as 66/ 39 with a pulse rate of 45 and sometimes its as high as 144/ 81 with a pulse of 70 and my pulse can be as high as 146. Im due to go to the doctor in a month as my heart rate was high last time i went. However having monitored my heart rate and pulse with a lood pressure monitior im now worried. Should i be concerned. Im an active, otherwise healthy individual :) I occasionally suffer from light headedness, tirdness and palpatations.