PHOENIX, July 11 (Phoenix Times Online) — Most adults have a resting heart rate between 60 and 100 beats per minute, according to the American Heart Association, Cleveland Clinic, the British Heart Foundation and Harvard Health. A resting heart rate above 100 beats per minute is called tachycardia, or a fast heart rate.
That number can matter because it is often a clue that something else is going on. Health groups say a fast resting pulse can happen for short-term reasons such as stress, anxiety, fever, dehydration, caffeine or other stimulants, poor physical conditioning, pregnancy and some medicines. It can also be linked to medical problems, including anemia, infection and an overactive thyroid. The American Heart Association also lists heart-related causes such as heart disease, heart muscle damage from a heart attack or heart failure, severe bleeding, chronic lung disease and very low blood pressure.
Why does it matter?
A fast pulse at rest does not point to one diagnosis. Yale Medicine cardiologist Srijan Shrestha, MD, said a person with a high resting heart rate may have palpitations, shortness of breath, dizziness or lightheadedness. But she also said some people have no symptoms at all.
Shrestha said anemia can be related to menstruation and blood loss in women. In older adults, she said, it may come from small gastrointestinal bleeds or colon cancer. Yale Medicine said doctors may treat the cause, such as iron supplementation for anemia or medication for hyperthyroidism.
When do doctors pay closer attention?
Harvard Health says clinicians usually do not worry unless the resting heart rate is consistently above 100 beats per minute in otherwise healthy people. Other health systems make a similar point: a single reading is less important than a pattern, and a fast pulse can be temporary if there is a clear reason such as illness, stress or stimulant use.
How is it checked?
Yale Medicine says a resting pulse can be checked at the wrist, inside the elbow, neck or top of the foot. The usual method is to count the beats for 15 seconds and multiply by four. If the pulse seems irregular, Yale Medicine says it can be counted for 30 seconds and multiplied by two, or counted for a full minute.
The basic takeaway from these medical groups is simple: a resting heart rate that stays above 100 is worth a closer look, but it is not a diagnosis by itself. Doctors use it as one more sign that can help point to the cause.
