What is the normal resting heart rate range for a healthy adult, and at what rate is tachycardia generally considered?

• A. 50–90 bpm; tachycardia >90 bpm
• B. 70–110 bpm; tachycardia >110 bpm
• C. 60–100 bpm; tachycardia >100 bpm
• D. 40–80 bpm; tachycardia >80 bpm

Answer: (C)

Normal resting heart rate for a healthy adult is typically 60–100 beats per minute. Tachycardia is generally defined as a resting heart rate above 100 bpm. This threshold helps distinguish normal physiological variation from an rate that may indicate an underlying issue or the need for further assessment. Some well-trained athletes may have resting rates below 60 bpm, which can be normal for them, but the 60–100 range covers the typical adult population. The other options either set the range too narrow or set the tachycardia threshold too low or too high, which would misclassify normal variation or miss true tachycardia.