‘I’m a Cardiologist—Here’s Why Your Heart Races at Night (and When It’s Time To Worry)’

Photo: Stocksy/Jimena Roquero
Have you ever collapsed into bed, ready for a good night's sleep, only for your heart to feel like it's doing gymnastics? If you feel your heart racing at night, you're likely not imagining things, and you're not alone.

You might just be super aware of your heart beating, and maybe picking up speed. Or you could be experiencing heart palpitations, which are sensations like unusual heart beating, fluttering, skipping a beat, or the feeling that your heart is doing a "flip" in your chest, according to the Cleveland Clinic.

However, these sensation are all pretty common and may not be a sign that something is wrong, says Mariell Jessup MD, FAHA, a cardiologist and chief science and medical officer at the American Heart Association. But if you're a little weirded out by your rapidly beating heart, Dr. Jessup breaks down what causes bedtime heart palpitations, how to reduce them, and when your heart pounding at night might be a cause for concern.

Experts In This Article

Why your heart races at night when you lie down

You may be experiencing heart palpitations throughout the day, but you're more likely to notice them when you get into bed and settle in for the night, the Cleveland Clinic says. However, there are a few bedtime-specific reasons your heart might be racing above your resting heart rate at night.

Drinking caffeine or alcohol, eating too close to bed, or smoking

Dr. Jessup says that common causes of nighttime heart flutters include drinking caffeine too late in the day, elevated blood sugar, or smoking. Caffeine can cause your heart to contract with more force. Eating too close to bedtime can cause your blood sugar to spike because your body is not as adept at digesting at night.

"Your body is less sensitive to insulin in the evening, and insulin helps control your blood sugar levels," Juliana Dewsnap, RD, LDN, CPT, and formerly the dietitian for Baze, previously told Well+Good. "[So], eating too close to bedtime may lead to varying blood sugar levels, which can impact your quality of sleep."

Body position

Body position also has an impact on heart rate and blood pressure. When you lay down, your cardiovascular system has to respond to the gravitational forces that shift when you change positions, whether that's standing, sitting, or laying down. It is also possible that laying on your left side can affect your heart's function, though further study is required for exact explanations, Dr. Jessup says.


Mental health factors like anxiety, depression, stress, and acute emotional reactions like anger can have a distinct impact on your heart rate. If you begin to think about your life's stressors or things troubling you when you lay down to sleep, it can cause your heart to race, says Dr. Jessup. Your heart can start racing from stress thanks to the activation of your sympathetic nervous system.

“Stress and anxiety can activate the sympathetic nervous system, which causes the release of neurotransmitters such as norepinephrine and epinephrine,” Heather Martin, DO, family medicine physician at telehealth platform K Health who specializes in hypertension (aka high blood pressure), previously told Well+Good. “These chemicals trigger the ‘fight or flight’ response, which is designed to prepare you for reacting to a dangerous situation, primarily by increasing heart rate and respiratory capability and dilating the eyes.”

At the same time, your internal calming systems get put on the back burner, which is a “decrease in parasympathetic activity—aka the calm 'rest and digest' processes—which also contributes to a faster heart rate, often felt as racing,” Erich G. Anderer, MD, chief of neurosurgery at New York University Langone Hospital in Brooklyn, previously told Well+Good.

The Centers for Disease Control and Prevention reports that chronically unmanaged mental health disorders like anxiety and depression can lead to heart diseases, so seek treatment for your mental health for the sake of both your brain and your ticker.


Can dehydration cause a high heart rate? Certainly. There's actually a direct connection between your hydration and your heart rate.

“Your heart is constantly pumping blood through your body—on average, around 7,600 liters daily,” Long Cao, MD, a board-certified cardiologist with Memorial Hermann in Houston, Texas, previously told Well+Good. “Staying well-hydrated helps your heart more easily pump blood to your muscles, which helps your muscles work more efficiently.” If you're not well-hydrated, your heart may try to compensate by beating faster, according to Dr. Cao.

That's part of the reason why one impact of alcohol can be an increased heart rate, since alcohol consumption is linked to dehydration.

Additionally, electrolytes are heavily involved in regulating your heartbeat, according to the Cleveland Clinic. When you're dehydrated, the body has a harder time balancing its electrolytes, which can impact your heartbeat and might explain why your heart races at night.

What can you do to ease your racing heart

If your heart palpitations are keeping you up at night, Dr. Jessup recommends you experiment with different sleeping positions—especially if you tend to lay on your left side. Laying on your back, sitting up, or sleeping on your right side might help the rhythm to right itself.

Additionally, getting up to drink a glass of water is a good idea, according to Dr. Jessup, especially if you realize you have had a lot of caffeine or alcohol—and maybe not enough water—that day.

You can also try some breathing exercises to calm yourself down if you're feeling stressed, or think your heart palpitations may be due to anxiety. You'll want to focus on slow breathing, which can help you activate the parasympathetic nervous system.

“In healthy people, we see a temporary increase in heart rate with inhalation followed by a decrease with exhalation,” says Dr. Anderer. “Slow breathing can also have direct influence on pressure receptors in the vascular and pulmonary systems and promote a state of relaxation, which tends to enhance the parasympathetic response throughout the body and allow you to ‘rest and digest.’”

When are heart palpitations a cause for concern

Occasional heart pounding, racing, or fluttering is pretty normal. But there are a few cases when you should go to the hospital for a rapid heart rate.

Heart palpitations can be a sign of an anxiety attack. These episodes are not an immediate risk to your physical health. Rather, they are a sign you should seek mental health care.

If you are experiencing chronic palpitations every time you go to bed, and you're hydrating, reducing stress levels, and monitoring caffeine intake—it's a good idea to talk to a doctor.

Sometimes heart palpitations can be signs of heart conditions like arrhythmia, heart valve disorders, thyroid conditions, or myocarditis. These conditions are chronic problems that require treatment, so be sure to reach out to a doctor if you feel strange heartbeats consistently.

In the moment, a racing heart could be a sign to tune in for signs of a heart attack. Heart attack signs include accompanying chest pain, dizziness, nausea, shortness of breath, or fainting. If you experience these symptoms in tandem with heart palpitations, seek treatment urgently.

It can be alarming to feel a weird sensation in your chest. Your mind might wander to the worst-case scenarios, but rest assured that slight changes in your heartbeat when you lay down are fairly common—as long as they're not chronic and no other symptoms arise. So next time your heart is doing gymnastics when you've settled in for some sleep, roll over or get some water, then snag those zzzs.

Well+Good articles reference scientific, reliable, recent, robust studies to back up the information we share. You can trust us along your wellness journey.
  1. Pan, Hongze et al. “Lying position classification based on ECG waveform and random forest during sleep in healthy people.” Biomedical engineering online vol. 17,1 116. 30 Aug. 2018, doi:10.1186/s12938-018-0548-7

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