Heart palpitations are moments when you become suddenly aware of your heartbeat in a way that feels abnormal. They can show up as a racing, pounding, fluttering, or flip-flopping sensation in your chest, and sometimes you feel them in your throat or neck. About 16% of all visits to a general practitioner involve palpitations as a complaint, making them one of the most common symptoms doctors encounter. Most of the time, they’re harmless and short-lived.
What Palpitations Actually Feel Like
People describe palpitations in several ways: a heart that’s beating too fast, skipping beats, pounding hard enough to notice, or doing a flip-flop that briefly catches your attention. Some feel a rapid flutter, while others notice a pause followed by a single strong thump. That thump happens because when the heart’s electrical signal fires too early, the next beat comes after a slightly longer pause and pushes out more blood than usual, creating that distinctive “skipped beat” sensation.
Palpitations can last a second or two, or they can stretch on for minutes. They might happen while you’re exercising, lying in bed at night, or sitting at your desk doing nothing in particular. The sensation itself is not pain. It’s more of an awareness, a sudden feeling that something in your chest is out of rhythm.
Why They Happen
Your heart relies on a precise electrical system to keep its chambers beating in sync. Two broad problems can disrupt that system. The first is abnormal impulse formation, where the cells that generate your heartbeat fire too quickly or at the wrong time. The second is a conduction disturbance, where the electrical signal gets caught in a loop and recirculates, causing the heart to beat faster than it should. Both of these can produce the sensations people recognize as palpitations.
But not all palpitations come from an electrical glitch. Many are triggered by something outside the heart entirely.
Stress and Anxiety
Anxiety activates your body’s fight-or-flight response, which directly increases your heart rate. Your autonomic nervous system floods your body with stress hormones that make the heart beat harder and faster. This is why palpitations often show up alongside other anxiety symptoms like rapid breathing, sweating, tense muscles, and trembling. In primary care studies, about 31% of palpitation cases are ultimately traced to anxiety or panic disorder rather than a heart problem.
Electrolyte Imbalances
Minerals like magnesium and potassium help regulate the timing of your heartbeat. Magnesium, specifically, controls how quickly the electrical gates in a key part of your heart’s conduction system open and close. Too little magnesium and those gates move faster, speeding up your heart rate. Too much and they slow down. Magnesium deficiency is very common, and it can create a feeling that your heart is beating out of sync.
Dehydration, intense exercise, heavy sweating, and poor dietary intake can all deplete these electrolytes. Alcohol and caffeine can also shift the balance enough to trigger noticeable palpitations in some people.
Other Common Triggers
Hormonal changes during pregnancy, menstruation, or menopause can bring on palpitations. Stimulants like caffeine and nicotine are well-known triggers. Fever, thyroid disorders, low blood sugar, and certain cold or asthma medications can all cause them too. Even a large meal can sometimes redirect enough blood flow to make the heart work noticeably harder.
When Palpitations Signal Something Serious
Of all palpitation cases evaluated in primary care, about 84% end up with a clear explanation. Roughly 43% turn out to be cardiac in origin. Most of those are premature heartbeats, which are extra beats that feel alarming but are almost always benign. However, some palpitations point to arrhythmias that need attention.
Atrial fibrillation is the most common significant arrhythmia. It causes the heart’s upper chambers to fire in a chaotic, disorganized pattern. Atrial flutter is related but more regular, with the upper chambers beating 250 to 350 times per minute. Paroxysmal supraventricular tachycardia (PSVT) causes sudden episodes of rapid heartbeat due to faulty electrical signals looping between the upper and lower chambers. Ventricular tachycardia, a fast regular beating in the heart’s lower chambers, is less common but more dangerous.
Palpitations accompanied by chest pain, fainting, severe dizziness, or significant shortness of breath are a different situation from isolated fluttering. Those combinations suggest the heart rhythm disturbance is affecting blood flow, and they warrant prompt medical evaluation.
How Palpitations Are Diagnosed
The challenge with diagnosing palpitations is that they often come and go unpredictably. A standard electrocardiogram (ECG) records your heart’s electrical activity for about 10 seconds, which is useful only if you’re having symptoms at that exact moment. If the ECG looks normal and your symptoms are intermittent, the next step is usually a portable monitor you wear at home.
A Holter monitor is the most common version. It continuously records your heart rhythm for 24 hours or longer. Research suggests that at least 10 hours of recording is necessary to reliably catch serious rhythm disturbances. During the monitoring period, you keep a diary of when you feel palpitations so the results can be matched to your symptoms. If 24 hours isn’t enough, event monitors and adhesive patch monitors can extend the recording period to days or even weeks, capturing episodes that happen less frequently.
The American College of Cardiology and American Heart Association recommend Holter monitoring as a first-line tool when palpitations can’t be explained by a patient’s history, physical exam, and resting ECG alone.
Stopping Palpitations in the Moment
For certain types of rapid heartbeat, particularly supraventricular tachycardia, physical techniques called vagal maneuvers can sometimes reset the heart’s rhythm on the spot. These work by stimulating the vagus nerve, which slows the heart rate by increasing parasympathetic tone.
The most well-known technique is the Valsalva maneuver: you take a deep breath and bear down hard, as if straining, for 10 to 15 seconds. A practical version involves blowing into a syringe until the plunger moves. The standard approach converts the rhythm back to normal about 20 to 40% of the time. A modified version, where you immediately lie flat and raise your legs after the straining phase, roughly doubles that success rate to around 40% or higher.
Other approaches that stimulate the vagus nerve include splashing ice-cold water on your face (which triggers the diving reflex) and coughing forcefully. These techniques are most effective for specific arrhythmias and won’t do much for palpitations caused by anxiety or caffeine, where the heart’s rhythm is actually normal but simply faster or more forceful than usual.
Reducing Palpitations Over Time
If your palpitations are linked to lifestyle triggers, the path forward is straightforward. Cutting back on caffeine, alcohol, and nicotine eliminates the most common stimulant-related causes. Staying well hydrated and eating foods rich in magnesium and potassium (leafy greens, nuts, bananas, avocados) helps maintain the electrolyte balance your heart depends on.
For anxiety-driven palpitations, addressing the anxiety itself is often more effective than focusing on the heart. Regular exercise, adequate sleep, and stress management techniques like slow breathing directly lower the baseline activity of your fight-or-flight system. When palpitations are traced to an arrhythmia, treatment depends on the specific type and how much it affects daily life, ranging from simple monitoring to procedures that correct the faulty electrical pathway.