PHOENIX, July 11 (Phoenix Times Online) — A resting heart rate is one of the simplest numbers to check, and it can offer a clue about what is going on in the body. The American Heart Association, Cleveland Clinic, the British Heart Foundation and Harvard Health all describe a normal adult resting heart rate as 60 to 100 beats per minute. A rate that stays above 100 at rest is commonly called tachycardia, or a fast heart rate.
That does not automatically mean a heart problem or an emergency. Harvard Health says clinicians usually do not worry unless the resting rate is consistently above 100 beats per minute. Cleveland Clinic and the British Heart Foundation note that exercise, stress, anxiety, caffeine and other stimulants can raise the pulse for a short time. Poor fitness, pregnancy and some medicines can also play a role.
When a high resting heart rate keeps happening, doctors look for the cause. The American Heart Association lists anemia, dehydration, chronic lung disease, severe bleeding, very low blood pressure, heart disease and damage related to a heart attack or heart failure among possible causes. Harvard Health, Cleveland Clinic and the British Heart Foundation also point to infection, fever and an overactive thyroid.
Yale Medicine cardiologist Srijan Shrestha, MD, says a fast resting heart rate may show up as palpitations, shortness of breath, dizziness or lightheadedness, but it may cause no symptoms at all. Yale Medicine also says anemia can be related to menstruation and blood loss, and in older adults it can sometimes come from small gastrointestinal bleeds or colon cancer.
How is it checked? Yale Medicine says a resting pulse can be measured at the wrist, inside the elbow, neck or top of the foot. Count the beats for 15 seconds and multiply by four. If the rhythm seems irregular, count for 30 seconds and multiply by two, or count for a full minute.
If a doctor decides tachycardia needs treatment, it usually focuses on the cause. Dr. Shrestha says iron supplementation may be used for anemia, and medication may be used for hyperthyroidism. Henry Ford Health’s Dr. Keteyian says people should see a doctor if their resting heart rate is above 100 or below 50 and there is no clear reason, such as regular exercise.
For most people, the main lesson is simple: a fast resting pulse is a signal to notice, not a reason to panic. If it keeps happening when the body should be at rest, clinicians use it as one clue in a broader checkup.
