You glance at your heart rate monitor during a tough run and an unusually high number jumps out at you. Should you be excited or concerned?

Tachycardia is the medical term for a heart rate over 100 beats per minute (BPM). It can be a sign of emotional distress or anxiety, anemia (low levels of iron in the blood), infections, dehydration, ...

In TODAY.com's Expert Tip of the Day, a cardiologist explains why a lower resting heart rate can be a good sign of heart health and how to improve this vital sign. Resting heart rate — the number of ...

The heart beats around 100,000 times a day, yet most people rarely think about how fast, or how efficiently it’s working, ...