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, ...

The human heart works quietly in the background, beating around 100,000 times a day. Most people notice it only during exercise, stress, or illness. Yet doctors say one simple number, the resting ...