Understanding a High Resting Heart Rate: Causes & What to Do

Question
Hi Dr. Manger,
I am jon, 35 years old, normal blood pressure and weighs around 110 lbs. I consider myself fit as i run for at least 30 minutes every other day and lift weights in the days between running. I recently ran and finished a 5k race without problems. but for the past year  i noticed i have a high resting heart rate, just right now sitting at my pc typing i checked by heart rate and its 100 beats per minute and usually when i wake up its around 90 beats per minute. I know my heart rate is abnormally high so my question is this - what are the implications of a high heart rate? Does this mean i am over trained and over fatigued? Does this present a health threat to me? if so how can i lower my heart rate? Please advice thanks

Answer
Jon,

There are many things that can cause your heart rate to increase.  Drugs such as caffeine and decongestants are very common culprits.  Some types of antidepressants can also have this effect.  Long term effects I am unaware of, though if you are without any medications, and athletic, I would expect your heart rate to be below 80.  It may be worth a trip to your doctor to get checked out and make sure there are no other factors in play, such as thyroid disorders.