What is the medical term for a resting heart rate below 60 beats per minute?

The medical term for a resting heart rate below 60 beats per minute is bradycardia.

The word comes from the Greek bradys, meaning slow, and kardia, meaning heart. In adults, clinicians commonly define bradycardia as a resting rate under 60 beats per minute, although the number alone does not establish that something is wrong. Heart rate varies with age, fitness, sleep, medications, and overall health.

Well-trained athletes and some healthy young adults may naturally have resting rates below 60 because conditioning makes the heart pump more efficiently. Bradycardia can also result from problems in the heart's electrical system, including sinus-node dysfunction or atrioventricular block. Certain medicines, such as beta blockers, can slow the rate as well.

Bradycardia differs from tachycardia, which means an abnormally fast resting rate, and from arrhythmia, the broader term for an irregular or abnormal rhythm. Symptoms such as fainting, dizziness, unusual fatigue, chest discomfort, or shortness of breath make slow heart rate more clinically concerning and warrant medical assessment.