Heart Beating Fast: What Does It Mean?   

Heart Beating Fast: What Does It Mean?

Man checking pulse

February 14, 2024

Clinical Contributors to this story:
Justin Lee, M.D.

It’s a well-known fact that getting your heart rate up with a few workouts a week is good for you. But what about times when you notice your heart racing, but you haven’t been exercising or doing anything physical?

Our expert Justin Lee, M.D., a cardiologist at Hackensack University Medical Center, tells us what’s normal regarding a higher heart rate and when you should consider seeing your doctor.

Less Concerning Reasons for a Fast Heart Rate

Sinus tachycardia is when your heart beats faster than usual due to exercise or other stimuli,” Dr. Lee says. “It’s your heart’s normal response. Your heart is beating faster because it needs to.” 

In addition to exercising, your heart may beat faster because of:

  • Dehydration. A large portion of your blood is made up of water. So when water is in short supply, the volume of your blood is lower, and your heart has to work harder to compensate.
  • Caffeine. Caffeine is generally safe for most people when consumed at low to moderate levels. However, if you ingest high amounts of caffeine, it can affect your nervous system and heart rhythm.
  • Emotions. Our emotions are powerful and cause bodily responses. If you are stressed or highly anxious, you may notice that your heart beats faster.

“While a racing heart can be bothersome, all of these normal responses generally will resolve on their own,” Dr. Lee says. “So there is no need to see a doctor.”

Fast Heart Rate Due to Arrhythmia

Sometimes people experience a pounding heart not caused by the heart responding to a normal situation. This is called an arrhythmia. “An arrhythmia is when you have a faster heartbeat due to a disease,” Dr. Lee says. 

There are various reasons why you may have an arrhythmia, but atrial fibrillation—also known as Afib—is the most common one

Arrhythmia can be caused by numerous conditions including:

  • Heart attack
  • Lung diseases
  • Thyroid issues
  • Infections
  • Leaky heart valves
  • Sleep apnea

When to See a Doctor

If you notice your heart is beating faster, see if it regulates on its own: 

  • Give yourself some rest
  • Drink water
  • Reduce your caffeine intake 

“If it persists, talk to your doctor to see if you have an arrhythmia, such as Afib,” Dr. Lee says.

Additionally, if you know you have one of the above conditions, you are at higher risk of arrhythmia. So if you experience a high heart rate, you should see your doctor.

Many arrhythmias come and go, so you may be tempted to ignore it. But if you are consistently experiencing moments of heart palpitations, don’t ignore it. “If you do have an arrhythmia, left untreated, it can weaken your heart,” Dr. Lee says. “This could lead to heart failure and other complications.”

Next Steps & Resources

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.


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