A Racing Heart While Resting: What You Should Know

It would probably be a shock to glance at your fitness tracker while chilling on the couch and notice your heart reaching 106 beats a minute. But health experts say that a number of things can cause a spike in your resting heart rate, including caffeine, anxiety and underlying health conditions.

​Read more:​ What's Your RHR and Why Should You Care?

Typically, a normal resting heart rate falls between 60 and 100 beats a minute, according to the Mayo Clinic. An abnormally fast resting heart rate — called tachycardia — happens when the upper or lower chambers of the heart beat more than 100 times a minute, explains Shoshana Ungerleider, MD, an internist who practices hospital medicine at California Pacific Medical Center in San Francisco.

"It is normal for your heart rate to rise during exercise or as a physiological response to stress, trauma or illness," says Dr. Ungerleider. "This is called sinus tachycardia." Not all types of tachycardia are benign, however. According to the Mayo Clinic, other types that come with health consequences include:

• ​Atrial fibrillation —​ a fast heart rate caused by disordered, irregular electrical impulses in the heart's upper chambers, known as the atria.
• ​Atrial flutter —​ when the atria of the heart beat rapidly but at a steady rate, resulting in weak atrial contractions.
• ​Supraventricular tachycardia —​ an abnormally rapid heartbeat originating somewhere above the heart's ventricles, which are the lower chambers.
• ​Ventricular tachycardia —​ a fast heart rate originating with abnormal electrical signals in the ventricles.
• ​Ventricular fibrillation —​ when fast, disordered electrical impulses cause the ventricles to quiver inefficiently instead of pumping blood that the body needs.
  

Dr. Ungerleider cites several factors that may increase your chances of developing tachycardia, including "anxiety or stress, anemia, hyperthyroidism, structural heart disease, an electrolyte imbalance, medication side effects, ingesting large amounts of caffeine, heavy alcohol consumption, fever, smoking or drug use (such as cocaine)."

How tachycardia is treated depends on what's causing it, Dr. Ungerleider says. "If you have a medical condition that causes an abnormally fast heart rate, there are various medications that a doctor may prescribe to lower the rate, including beta blockers, calcium channel blockers or digoxin," she says.

"Also, if you have an underlying medical condition (such as anemia, hyperthyroidism or heart disease) that causes elevated heart rate, treating the underlying medical problem can lower your heart rate," she adds.

If stress and anxiety are causing your heart to race, according to the National Institute of Mental Health, that could signal an anxiety disorder and may be worth seeking professional help — especially if your anxiety worsens over time and interferes with daily activities like relationships, school and work. Treatment may include medication and cognitive behavioral therapy, which can help you change patterns of thoughts, behaviors and reactions to your fears, the NIMH explains.

If your rapid resting heart rate is exacerbated by your beverage choices, cutting back might be your best bet. For instance, drinking too much alcohol can be a culprit when it comes to a fast resting heart rate, according to a 2017 review article published in ​Alcohol Research​. And according to the current ​Dietary Guidelines for Americans​, if you consume alcohol, you should do so in moderation — defined as no more than two drinks a day for men and one drink daily for women.

Likewise, if you experience a rapid heart rate from caffeinated beverages like coffee and energy drinks, you're likely consuming too much caffeine and could benefit from slowly reducing your intake, according to the Cleveland Clinic. The ​Dietary Guidelines​ recommend limiting caffeine intake to 400 milligrams daily, equivalent to three to five eight-ounce cups of coffee, and less than 300 milligrams (two to three cups of coffee) if you're pregnant.

The burning question remains: What symptoms are worrisome enough that you should you see your doctor?

"If you notice that you have an elevated heart rate while at rest consistently above 100 beats per minute — but you aren't sick, exercising or stressed — it is important to let your doctor know," Dr. Ungerleider warns. "If you are experiencing shortness of breath, dizziness or fainting, fluttering in your chest or chest pain, this could be related to a problem with your heart."

​Read more:​ What's Causing Your Elevated Heart Rate?