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Palpitations: Are Your Heartbeats Normal or Dangerous?

Most palpitations are benign extra beats, but some signal arrhythmias that can cause stroke or sudden cardiac death. The pattern is key to diagnosis.

Written by Suman Konda, PharmD, Clinical Pharmacist · Editorial policy · Not medical advice

Last updated: · How we check our content

Most common cause
Ectopic beats (benign)
Serious cause
AF, SVT, VT
Key test
ECG: ideally during symptoms
Emergency sign
Palpitations + syncope
Call 999/911Palpitations with chest pain, breathlessness, fainting, or near-fainting. Also seek emergency care for regular fast heartbeat lasting more than 30 minutes.

Types of Palpitations

TypeFeelLikely Cause
Ectopic beatsSkipped beat or thumpAtrial or ventricular ectopics (usually benign)
Regular fast rateRacing, starting/stopping suddenlySVT (supraventricular tachycardia)
Irregular fast rateChaotic, fast, irregularAtrial fibrillation
Slow irregularMissed beats, slowHeart block
Exercise-inducedRapid HR during exertionAVNRT, WPW, inappropriate sinus tachycardia
Related to anxietyRacing HR with panicSinus tachycardia, anxiety disorder
Capture It on ECGThe diagnosis depends on recording the rhythm during symptoms. A 24-hour (Holter) monitor captures infrequent events; a 7-day or 4-week monitor catches less frequent palpitations.
Are palpitations dangerous?
Most are benign ectopic beats worsened by caffeine, stress, or fatigue. However, palpitations with fainting, chest pain, or that occur in people with structural heart disease require urgent investigation.
What is SVT?
Supraventricular tachycardia: a sudden, rapid heart rate (often 150–250 bpm) that starts and stops abruptly. It's rarely dangerous but very uncomfortable. Treated with vagal manoeuvres or medications.
Can caffeine cause palpitations?
Yes. Caffeine stimulates the heart and can trigger ectopic beats or worsen existing arrhythmias. Reducing coffee, energy drinks, and tea often reduces palpitation frequency.
What is a Holter monitor?
A portable ECG device worn for 24 hours (or up to 4 weeks) to capture heart rhythm during daily activities and symptoms. It's the main tool for diagnosing intermittent arrhythmias.
Chest PainCardiac red flags

Related reading

Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.

What palpitations feel like, and why the description matters

Describing the rhythm is genuinely diagnostic, because different arrhythmias feel different. A single thump or a sensation that the heart has skipped and then restarted usually reflects an ectopic beat, which is common and generally harmless. A fast, regular racing that starts and stops abruptly, like a switch, suggests a supraventricular tachycardia. A fast, completely irregular rhythm raises the possibility of atrial fibrillation. A pounding that builds and fades over minutes, often with sweating and a sense of dread, more often reflects anxiety or an adrenaline surge than a primary rhythm problem.

Tapping the rhythm out on a table for your doctor is more informative than it sounds, and so is recording an episode. Most modern phones and smartwatches can capture a single-lead trace, and while these should not be used to self-diagnose, a recording made during symptoms is often the piece of evidence that resolves the question.

Common triggers worth removing before testing

  • Caffeine, including energy drinks and pre-workout supplements, which frequently contain far more than coffee.
  • Alcohol, particularly binge drinking, which has a well-recognised association with atrial fibrillation.
  • Nicotine from any source, and stimulant decongestants such as pseudoephedrine.
  • Poor sleep and dehydration, both of which lower the threshold for ectopic beats.
  • Thyroid over-replacement, a common and easily missed cause in people taking levothyroxine.

Features that need prompt assessment

Palpitations accompanied by fainting or near-fainting, chest pain, or breathlessness at rest should be assessed urgently, as should any episode in someone with known heart disease, a weak heart muscle, or a family history of sudden cardiac death under 50. Palpitations that begin during exertion, rather than after it, deserve particular attention. Isolated skipped beats in an otherwise well person with a structurally normal heart are usually benign, but that reassurance depends on the assessment having been done.