08/19/2026
Your heart rate naturally speeds up when your body needs more oxygen—during exercise, excitement, stress, or even when you’re fighting an illness.
But what does it mean when your heart is beating fast while you’re at rest?
Tachycardia generally refers to a heart rate greater than 100 beats per minute (bpm) at rest in adults.
A faster heart rate can have many causes. Exercise, fever, dehydration, stress, caffeine, certain medications, and other factors can temporarily increase your heart rate. In other cases, tachycardia may be related to an abnormal heart rhythm or an underlying medical condition.
Some people may experience:
⚡ A racing or pounding heartbeat
🫁 Shortness of breath
💫 Dizziness or lightheadedness
❤️ Chest discomfort
😴 Weakness or fatigue
🩺 Or sometimes, no noticeable symptoms at all
The number is only part of the story. Your healthcare provider may also consider when the fast heart rate occurs, how long it lasts, whether the rhythm is regular, your symptoms, and what may be causing it.