Caffeine vs WaterHeart
Caffeine and Heart Palpitations: What the Latest Research Says
Caffeine heart palpitations are common, but a 2023 NEJM trial found coffee didn't raise extra atrial beats. What the evidence shows and when to see a doctor.
The short answer
- Caffeine can cause heart palpitations in some people, and the FDA lists palpitations as a sign of too much caffeine. But for most people, moderate coffee doesn't cause dangerous heart rhythms.
- In the 2023 CRAVE trial (NEJM), coffee days did not significantly increase extra beats from the heart's upper chambers (58 vs 53 a day), but did increase extra beats from the lower chambers (154 vs 102 a day).
- In a study of 386,000 UK adults, each extra daily cup of coffee was linked to a 3% lower risk of arrhythmia.
- Get urgent help for palpitations with chest pain, breathlessness or fainting. See a doctor if they keep coming back, last more than a few minutes, or you have a heart condition.
A fluttering, thumping or "skipped" heartbeat after a strong coffee is an unsettling feeling, and caffeine heart palpitations are one of the most common reasons people cut back. For years, doctors routinely told patients with palpitations to avoid caffeine.
The research of the last decade paints a more nuanced picture. Coffee does change heart rhythm a little, in specific ways, but for most healthy people moderate amounts don't raise the risk of arrhythmia, and may even be linked to a lower risk. Energy drinks are another matter.
This article is general information, not medical advice. If you have palpitations, a heart condition or take heart medication, talk to your doctor.
What heart palpitations are
Palpitations are when you become aware of your own heartbeat. According to the NHS, it can feel like your heart is racing, pounding, fluttering, or irregular with skipped or extra beats, in your chest, neck or throat. They're common and usually not a sign of anything serious.
Many "skipped beats" are actually extra beats that come slightly early:
- Premature atrial contractions (PACs) start in the upper chambers.
- Premature ventricular contractions (PVCs) start in the lower chambers.
The pause after an early beat, and the stronger beat that follows, is what you feel as a "thump" or "flip". Most people have some every day without noticing.
Coffee and heart palpitations: the CRAVE trial
The best direct evidence comes from the CRAVE trial, published in the New England Journal of Medicine in 2023. Researchers at UC San Francisco fitted 100 healthy adults with a continuous heart monitor, a step-counting wristband and a glucose monitor. For 14 days, text messages randomly told each person to either drink caffeinated coffee or avoid caffeine that day. Because everyone was compared with themselves, this is much stronger evidence than a survey.
| Measure (per day) | Coffee days | No-caffeine days | Result |
|---|---|---|---|
| Extra atrial beats (PACs) | 58 | 53 | No significant difference |
| Extra ventricular beats (PVCs) | 154 | 102 | About 50% more |
| Steps | 10,646 | 9,665 | About 1,000 more |
| Sleep | 397 min | 432 min | About 36 minutes less |
| Blood glucose | 95 mg/dL | 96 mg/dL | No difference |
So coffee didn't significantly increase PACs, the trial's main outcome, but it did increase PVCs. Occasional PVCs are common and often harmless in people with a healthy heart, but they're exactly the kind of beat you might notice as a palpitation. That may explain why some people clearly feel coffee in their chest, even though it isn't doing them obvious harm. The 36 minutes of lost sleep is worth noting too; more on that in how caffeine affects sleep, and you can check what an afternoon cup leaves at bedtime with the bedtime caffeine calculator.
Does caffeine cause arrhythmia long term?
Two large studies suggest regular coffee drinking doesn't raise the risk of heart rhythm problems:
- UK Biobank, 2021. Among 386,258 adults followed for about 4.5 years, each additional daily cup of coffee was associated with a 3% lower risk of arrhythmia, including atrial fibrillation and supraventricular tachycardia. Genetic differences in caffeine metabolism didn't change the result.
- Cardiovascular Health Study, 2016. In 1,388 older adults who wore a 24-hour heart monitor, habitual coffee, tea and chocolate intake was not linked to more PACs or PVCs.
These are observational studies, so they can't prove coffee protects the heart. But together with CRAVE, they make it unlikely that moderate coffee causes dangerous rhythm problems in most people. A 2018 review in JACC: Clinical Electrophysiology reached a similar view: many widely held beliefs about caffeine and arrhythmia aren't supported by the evidence.
Energy drinks are different
Energy drinks deliver a lot of caffeine quickly, often with other stimulants. In a 2019 randomized trial, 34 healthy young adults drank 32 oz (about 950 ml) of energy drink within an hour. Compared with a placebo drink, the energy drinks raised blood pressure and prolonged the QTc interval, a measure of how the heart recharges between beats that's linked to dangerous rhythms when it's too long.
For perspective, here's how the doses compare:
| Drink | Size | Caffeine |
|---|---|---|
| Single espresso | 1 oz (30 ml) | 63 mg |
| Drip coffee | 8 oz (240 ml) | 95 mg |
| Red Bull | 8.4 oz (250 ml) | 80 mg |
| Monster | 16 oz (473 ml) | 160 mg |
| Celsius | 12 oz (355 ml) | 200 mg |
| Caffeine pill | 1 tablet | 200 mg |
| Bang | 16 oz (473 ml) | 300 mg |
| Starbucks Pike Place, Grande | 16 oz (473 ml) | 310 mg |
If you get palpitations, a single drink of 200 mg or more, or several energy drinks close together, is the most likely culprit. See the energy drink caffeine comparison for more brands.
If coffee gives you palpitations
- Look at the dose, not just the drink. A Grande filter coffee has five times the caffeine of an espresso. The caffeine content chart shows the big ones.
- Keep to moderate amounts. The FDA's figure for most adults is up to 400 mg a day; if you're sensitive, you may do better well below that. See how much caffeine is too much.
- Avoid energy drinks and caffeine pills. They deliver a large dose all at once.
- Check the other triggers. The NHS lists stress and anxiety, lack of sleep, alcohol, nicotine, strenuous exercise and some medicines. Caffeine often arrives alongside them. If anxiety is part of it, see caffeine and anxiety.
- Test it. Cut caffeine for two weeks, then reintroduce a normal cup. If palpitations return reliably, you have your answer. Taper rather than stopping abruptly (see how to cut back on caffeine).
In Caffeine vs Water, logging each drink as you have it lets you look back at how much you'd had when palpitations happened, which is useful to share with your doctor.
When to see a doctor about palpitations
Based on NHS guidance:
- Call 911 (US), 999 (UK) or your local emergency number if you have palpitations with chest pain, shortness of breath, or feeling faint or fainting, or palpitations that don't go away.
- See a doctor if palpitations keep coming back or are happening more often, last longer than a few minutes, or if you have a heart condition or a family history of heart problems.
Palpitations can also come from things like anemia, an overactive thyroid or a heart rhythm problem, so persistent symptoms are worth checking even if you suspect coffee. A doctor may suggest an ECG or a wearable heart monitor to see what's actually happening.
Frequently asked questions
Can caffeine cause heart palpitations?
Yes. Caffeine can cause palpitations in some people, especially at high doses or from energy drinks. In the 2023 CRAVE trial, coffee increased extra ventricular beats (PVCs), which many people feel as palpitations, but didn't significantly increase extra atrial beats.
Are coffee and heart palpitations dangerous?
For most healthy people, no. Large studies have found moderate coffee drinking isn't linked to a higher risk of arrhythmia, and one of 386,000 adults found a slightly lower risk. Palpitations with chest pain, breathlessness or fainting need urgent medical attention.
How long do caffeine palpitations last?
They usually ease as caffeine levels fall. Caffeine peaks about 45 minutes after a drink and its half-life is around 5 hours, so effects can linger for several hours. Palpitations that last more than a few minutes at a time, or keep coming back, are worth checking with a doctor.
Can energy drinks cause heart problems?
In a 2019 randomized trial, drinking 32 oz of energy drink within an hour raised blood pressure and prolonged the QTc interval in healthy young adults. People with heart conditions should avoid them.
Should I stop coffee if I have palpitations?
Not necessarily. Try cutting back or pausing caffeine for two weeks to see if symptoms change, and see a doctor if palpitations are frequent, long-lasting or come with other symptoms.
Sources
- Marcus GM, et al. Acute effects of coffee consumption on health among ambulatory adults (CRAVE). N Engl J Med, 2023.
- Kim EJ, et al. Coffee consumption and incident tachyarrhythmias: reported behavior, mendelian randomization, and their interactions. JAMA Intern Med, 2021.
- Dixit S, et al. Consumption of caffeinated products and cardiac ectopy. J Am Heart Assoc, 2016.
- Voskoboinik A, et al. Caffeine and arrhythmias: time to grind the data. JACC Clin Electrophysiol, 2018.
- Shah SA, et al. Impact of high volume energy drink consumption on electrocardiographic and blood pressure parameters: a randomized trial. J Am Heart Assoc, 2019.
- NHS. Heart palpitations.
- U.S. FDA. Spilling the Beans: How Much Caffeine is Too Much?
General wellness information, not medical advice. If you're pregnant, have a heart condition, or take medication that affects caffeine, check your limits with a doctor.