What we physicians tell patients should be based on evidence, but that doesn’t always happen. A good example is when patients ask what their pulse rate should be and we tell patients between 60 and 100—a range that has been in the medical literature for ages but is not based on science. Even the Mayo Clinic website wrongly says a normal pulse rate is 60 to 100.

Each time your heart contracts to pump blood through your arteries, a pulse occurs that can be palpated and sometime seen. You can check your pulse by lightly pressing the tips of your index and middle fingers against the carotid arteries in your neck, on either side of your wind pipe (trachea). You can also feel your pulse by placing tips of the the same 2 fingers against the radial artery, located on the thumb side of the palm surface of your wrist, about 1 ¼ inches above the joint. While looking at your watch, count your pulse for 15 seconds and multiply by 4, which gives you your pulse rate—the number of pulsations (heart beats) per minute.

In spite of the medical dictum of normal pulse being between 60 and 100, a resting pulse rate of 90 is clearly abnormal, and a rate in the 50s or even 40s can be very normal. For example, well-conditioned athletes have resting pulse rates in the 40s and 50s, and sometimes even the 30s.

Dr. Michael Greger’s website nutritionfacts.org describes studies that show that for every 10 heart beats per minute over 60, premature death (death that occurs earlier than the average American man or woman) increases by 10 to 20 percent. If your resting heart rate is in the 90s, your rate of sudden cardiac death is five times higher — about the same risk as if you smoked. Conditions that can cause an elevated pulse rate include:

• exercise — although if you are in good cardiovascular condition the rate should drop back to baseline shortly after stopping exercise
• poor cardiovascular conditioning
• anxiety or stress (“flight or fight” response)
• anemia
• low oxygen level
• pain
• dehydration
• stimulants such as caffeine and ephedrine-like drugs in OTC cold preparations
• hyperthyroidism (an overactive thyroid gland)
• withdrawal from alcohol and certain other substances

Unless you’re a well-conditioned athlete, be aware of conditions that could cause a slow heart rate — less than 60:

• heart block—a blockage in the heart’s electrical conduction system
• hypothyroidism (an underactive thyroid gland)
• certain prescription drugs such as beta-blockers

Your pulse rate should be regular.  It you have “skipped beats” or other irregularities, check with your PCP, who will order an EKG to determine what kind of irregularity you have — some such as atrial fibrillation are worrisome and others aren’t.

In summary, check with your PCP if your pulse rate is irregular; it it’s less than 60 (unless you’re a well-conditioned athlete); or if your resting pulse rate is greater than 70.

Dr. Greg Feinsinger is a retired family physician who started the non-profit Center For Prevention and Treatment of Disease Through Nutrition. For questions or to schedule a free consultation about nutrition or heart attack prevention contact him at gfmd41@gmail.com or 970-379-5718.