What Causes Heart Palpitations — and Are They Dangerous?

You’re sitting at home at night, maybe watching TV or checking your phone, when suddenly your heart feels weird.  

Maybe it feels like it skipped a beat or added an extra beat. Maybe it feels faster or harder than usual. You’re trying not to worry, but it’s your heart, after all, so you’re starting to feel kind of anxious.  

You’re likely experiencing heart palpitations. Here’s some information to help get you started — including when they’re a sign of something serious.

What heart palpitations are

So what exactly are heart palpitations — do they mean something is wrong with your heart?  

It’s important to distinguish palpitations (which are a symptom) from arrhythmias (which are true abnormal heart rhythm conditions). In many cases, heart palpitations aren’t actually an abnormal heart rhythm, says Babak Nazer, MD, a cardiac electrophysiologist at the UW Medicine Heart Institute who specializes in treating heart rhythm disorders, also known as arrhythmias. He also directs the UW Translational Electrophysiology Laboratory.

“Palpitations are just an abnormal sensation of a heartbeat, but often your heartbeat itself is normal,” he says. “You’re just feeling your heart beating in your chest differently than you usually do.”  

That heightened awareness means you may perceive a change in your heartbeat that is actually normal and doesn’t signify any underlying health issues. Since most of us don’t go about our days hyper-aware of what our heartbeats feel like, just the act of noticing them can cause alarm.  

However, sometimes heart palpitations are actually from an arrhythmia where the heart beats faster or slower than normal (doctors consider a normal heart rate to be 60 to 100 beats per minute), follows an irregular pattern or has extra beats.  

Arrhythmias are something to watch for because they may point to an underlying medical condition and may mean there is an increased risk of stroke or other cardiac events down the road. Thus, while palpitations don’t always correspond to true arrhythmias, doctors have to rule that out first, usually using a heart monitor. (More on that in a bit.)  

“We call this making a ‘symptom-rhythm correlation,’” says Nazer.  

What heart palpitations feel like

Everyone feels palpitations differently. For some people, their heart may feel like it’s beating faster or stronger; for others, it may feel like it’s flip-flopping or skipping a beat.  

It’s more common to feel palpitations at night when the body is at rest, especially if someone is lying down on their side, which brings the heart closer to the chest wall and turns the wall into a sort of drum.  

“Anecdotally, young people are much more likely to feel even single arrhythmias, such as a single extra beat, while older patients are more likely to have a true arrhythmia they don’t feel. We don’t really know why that is,” Nazer says.  

Feeling palpitations during exercise is also common. Less common is feeling them during mild activity, like walking or cleaning around the house.  

What causes heart palpitations

There are many things that can cause your heart to feel a little off, some of which are mild and a few of which are more serious. Here are a some of the most common:  

• Dehydration
• Drinking too much caffeine or alcohol
• Smoking or using drugs (including marijuana)
• Exercising
• Having a fever or respiratory illness

One thing to note about caffeine, since coffee (and a lot of it) is a staple for many PNW-ers: While doctors used to assume caffeine caused or worsened arrhythmias, recent research tells a different story. 

Caffeine may indeed make you notice your heartbeat more — and it can slightly increase premature ventricular contractions (PVCs), a usually benign type of extra beat. But for many people, it can actually decrease true arrhythmias like atrial fibrillation, Nazer says.

“Because of this research, I’ve pivoted from telling people to cut down on caffeine to telling my patients there’s no need to avoid caffeine unless they don’t like how it makes them feel,” he says.

Heart palpitations and anxiety  

Another common thing that can cause weird feelings in your chest? Anxiety. Palpitations are often accompanied by anxiety and symptoms such as a sense of impending doom, stomach upset, feeling tired and having trouble sleeping, and even trembling or sweating. (And yes, this can sometimes be hard to tell apart from heart problems.) 

While anxiety alone can cause palpitations, Nazer stresses that dismissing palpitations as a symptom of anxiety without an exam or further testing is a bad idea. If you go to a doctor and they don’t take your symptoms seriously, it’s a good idea to advocate for yourself and get a second opinion.

“Palpitations should always be taken seriously, and if you notice new ones, you should at least report them to your primary care provider,” Nazer says. “Calling it benign is a diagnosis of exclusion, meaning we have to exclude other possibilities first.”  

This is where it gets tricky: Anything that can cause non-dangerous palpitations can also trigger an arrhythmia. Some underlying causes of arrhythmia are usually harmless, like an extra electrical pathway in the heart that causes a fast heart rate, but others are more serious, such as heart disease or diabetes.  

Do you have an arrhythmia?

The only way to know for sure if you have an arrhythmia or not is to talk with a doctor or try wearing a heart monitor (more on that shortly). However, there are other signs of arrhythmias that you can watch for.

If your heartbeat changes suddenly, if the palpitations are persistent and recurring or severe enough to stop you in your tracks, those are all signs that you have an arrhythmia.  

Other symptoms that can occur with arrhythmias are lightheadedness or dizziness, sweating, shortness of breath, chest pain or difficulty exercising — and if you have any of these symptoms, it’s especially important to get checked out.

Arrhythmias are more common in older adults, but anyone, even children can get them. 

What to do if you’re having heart palpitations

First, look for any patterns or lifestyle triggers for your palpitations. If they seem to hit only when you’re doomscrolling, for example, that probably means they’re due to anxiety and something you could resolve by talking with a therapist or learning coping techniques.

Try to track the frequency of your palpitations and let your doctor know so they can order a heart monitor of sufficient duration. These monitors come in 24-hour, 48-hour, 7-day, 14-day and 30-day durations, and are fairly easy to wear. For example, if you only notice palpitations once a month, your doctor is much more likely to order a 30-day monitor than a 24-hour one.

If your palpitations are rarer or harder to pin down, or the monitor your provider ordered doesn’t catch them, Nazer recommends you also consider an at-home rhythm monitoring device, which you can buy easily online.

The at-home devices are fairly sophisticated and mimic getting an electrocardiogram, or EKG, at your doctor’s office. They can also tell you if it’s possible that you have an arrhythmia. Apps are similar, except they work through your smartwatch.  

However, if you’re more concerned about your palpitations, have other symptoms with them or have an underlying medical condition, it’s important to go to the doctor.

How to treat heart palpitations

If your app or at-home device hasn’t noted any irregular heartbeats or your doctor tells you that you don’t have an arrhythmia — but you’re still getting palpitations sometimes — it’s probably time to revisit the causes of palpitations and try to figure out where yours are coming from.

Drinking multiple cups of coffee a day? It might be time to tone it down a bit. Having lots of anxiety? It could be helpful to consult with a mental health specialist about medication or starting therapy.  

For people who are diagnosed with an arrhythmia, treatment largely depends on which arrhythmia you have.  

More serious arrhythmias, such as atrial fibrillation, should be treated with medication or a procedure known as cardioversion, which involves shocking the heart back into a normal rhythm. Another option is catheter ablation, a procedure that involves a doctor burning away a portion of heart tissue where the irregular heartbeat originates. Cardioversion and ablation may sound a little freaky, but they’re very safe and don’t involve surgery; you can usually go home the same day.

The most important point is that you seek answers, either from an app or from a doctor’s visit, instead of chalking your palpitations up to anxiety or stress.  

This article was originally published February 17, 2021. It has been reviewed and updated with new info.