A heart palpitation is the sensation of your heart beating in a way you wouldn’t normally notice. It can feel like a flutter, a skip, a sudden thud, or a racing in your chest, neck, or throat. Most palpitations are harmless and last only seconds, though they can be unsettling when they catch you off guard. What you’re actually feeling is abnormal movement of the heart within your chest, whether that’s an extra beat, a skipped beat, or a temporary change in rhythm or force.
What’s Actually Happening in Your Heart
Your heart beats roughly 100,000 times a day, driven by electrical signals that keep its chambers contracting in a coordinated rhythm. A palpitation happens when something briefly disrupts that rhythm or changes how forcefully the heart contracts. The most common type is a premature beat, where the heart fires an extra contraction slightly earlier than expected. This is followed by a brief pause as the heart resets, then a stronger-than-normal beat as the chamber empties a larger volume of blood. Interestingly, what most people perceive as the “skipped” beat is actually that forceful recovery beat, not the premature one.
These premature beats can originate in either the upper chambers (atria) or the lower chambers (ventricles). In people with a structurally normal heart, premature ventricular contractions carry no increased risk of death. They’re extremely common and often happen without any identifiable cause.
What Palpitations Feel Like
Not all palpitations feel the same, and the specific sensation can hint at what’s going on electrically. A single “skip” or brief pause followed by a thump typically points to a benign extra beat. A rapid, regular pounding that you can feel in your neck often suggests a type of fast rhythm originating above the ventricles. A fast but irregular fluttering may indicate atrial fibrillation, where the upper chambers quiver chaotically instead of contracting in sync.
Some people notice palpitations more at night, often because they’re lying quietly without distractions and become more aware of their heartbeat. This is usually benign. Others feel them during or after exercise, during moments of stress, or seemingly out of nowhere while sitting at a desk.
Common Triggers
Several everyday substances and situations can set off palpitations. Caffeine is the one people worry about most, but the evidence is more reassuring than you might expect. Both observational studies and randomized trials have found that drinking caffeinated beverages in typical amounts does not increase the risk of triggering abnormal heart rhythms. That said, high-dose caffeine from energy drinks is a different story and worth avoiding if you’re prone to palpitations. One or two cups of coffee in the morning is generally fine for most people.
Alcohol is a more reliable trigger. For people with a history of atrial fibrillation, experts recommend no more than three alcoholic drinks per week. Even in people without a known rhythm disorder, a night of heavy drinking can provoke noticeable palpitations, sometimes called “holiday heart.” Nicotine, decongestants, and some asthma medications can also act as stimulants to the heart.
Beyond substances, dehydration and electrolyte imbalances play a role. Potassium and magnesium are critical for maintaining the electrical stability of heart cells. When potassium drops below 3.5 mEq/L or magnesium falls below normal levels, the heart’s electrical system becomes more irritable and prone to misfiring. This can happen after intense exercise, prolonged vomiting or diarrhea, or with certain medications like diuretics.
Medical Conditions That Cause Palpitations
Sometimes palpitations are a symptom of something happening outside the heart. An overactive thyroid gland is one of the classic examples. Excess thyroid hormone directly affects the heart’s electrical system by altering ion channels in heart muscle cells and resetting the pacemaker cells that control your heart rate. The combined effect can increase the heart’s output by 50% to 300% above normal, producing a noticeably fast or pounding heartbeat, sometimes progressing to atrial fibrillation.
Anemia, where your blood carries less oxygen than normal, forces the heart to pump faster and harder to compensate, which you may feel as palpitations or a racing pulse. Fever and infections can do the same thing by raising your metabolic demands. Hormonal shifts during pregnancy, menstruation, or menopause are another frequent trigger that people don’t always connect to their heart symptoms.
Anxiety and panic attacks deserve special mention because they create a feedback loop. Stress hormones like adrenaline speed up the heart and increase the force of each beat. You notice the pounding, which makes you more anxious, which releases more adrenaline. In emergency department studies, a substantial portion of palpitation cases turn out to have anxiety as the primary driver, though it’s important not to assume this without ruling out other causes first.
How Palpitations Are Diagnosed
The challenge with palpitations is that they’re often gone by the time you see a doctor. A standard electrocardiogram (ECG) captures only about 10 seconds of your heart’s rhythm, so unless you’re having palpitations during the test, it may come back normal. That’s why doctors often use portable monitors.
A Holter monitor is a small device you wear for 24 to 48 hours that continuously records your heart rhythm. Studies show these monitors have a diagnostic yield of about 68%, meaning they capture clinically useful information in roughly two out of three patients. There’s no significant difference in detection rates between wearing one for 24 hours versus 48 hours. If your palpitations happen less frequently, an event monitor or a longer-term patch monitor worn for up to two weeks may be more useful, since it only records when you activate it or when it detects an abnormal rhythm.
Blood tests for thyroid function, electrolyte levels, and blood count are standard parts of the workup, since they can reveal treatable causes that have nothing to do with the heart’s wiring.
When Palpitations Are Serious
Most palpitations are not dangerous. But certain accompanying symptoms change the picture. Palpitations combined with dizziness, lightheadedness, or fainting suggest the rhythm disturbance is significant enough to reduce blood flow to the brain. Chest pain alongside palpitations also warrants emergency evaluation. A sudden collapse or loss of consciousness is the most urgent red flag and calls for immediate emergency care.
Your personal history matters too. People with known heart disease, a structural heart abnormality, or a family history of sudden cardiac death or inherited rhythm disorders are at higher risk for serious arrhythmias. In one emergency department study of 215 patients presenting with palpitations, 37% had a serious underlying cause, which underscores why evaluation is worthwhile even when the sensation itself feels brief or mild.
Stopping Palpitations in the Moment
If you feel a sudden racing heartbeat, a set of techniques called vagal maneuvers can sometimes slow it down. These work by stimulating the vagus nerve, which acts as a brake on the heart’s natural pacemaker. The most well-known technique is the Valsalva maneuver: take a breath and bear down hard, as if you’re straining during a bowel movement, and hold for 15 to 20 seconds. Another approach is the diving reflex, triggered by splashing ice-cold water on your face or briefly submerging your face in cold water.
These techniques are most effective for a specific type of fast rhythm called supraventricular tachycardia. If your palpitations are caused by simple premature beats, they’ll typically resolve on their own within seconds. For people whose palpitations are triggered by stress or anxiety, slow diaphragmatic breathing can help lower adrenaline levels and calm the heart rate over a few minutes.
Reducing Palpitations Over Time
For most people with benign palpitations, lifestyle adjustments are the first and often the only step needed. Staying well hydrated, maintaining adequate potassium and magnesium through foods like bananas, leafy greens, nuts, and beans, and getting consistent sleep all help stabilize the heart’s electrical environment. Limiting alcohol to a few drinks per week and avoiding energy drinks or excessive caffeine removes two of the most common chemical triggers.
Regular exercise, somewhat counterintuitively, tends to reduce palpitations over time by improving the heart’s overall efficiency and lowering resting adrenaline levels. Managing chronic stress through consistent physical activity, adequate sleep, or relaxation practices addresses one of the most persistent underlying drivers. For people whose palpitations are frequent, disruptive, or linked to a specific arrhythmia, treatments ranging from medication to catheter-based procedures can target the problem directly.