Heart palpitations are almost always harmless. In cardiac evaluation settings, only about 4% of patients investigated for palpitations and chest pain turn out to have a cardiac diagnosis. That said, the sensation is real and unsettling, whether it feels like your heart is racing, fluttering, skipping a beat, or pounding in your chest. The cause usually comes down to something your body is reacting to, from stress and caffeine to hormonal shifts and low electrolytes.
What Palpitations Actually Feel Like
Most palpitations are premature heartbeats, where the signal telling your heart to beat arrives a fraction too early. This creates a brief pause followed by a stronger-than-normal beat as your heart resets to its regular rhythm. That’s the “skipped beat” or “thud” sensation. Other times, you may notice a sustained fast or fluttery feeling that lasts seconds to minutes. Both patterns are common and, on their own, rarely indicate a problem.
Stress and Anxiety
Anxiety is one of the most frequent triggers. When you’re stressed or anxious, your body releases adrenaline, which speeds up your heart rate and makes each beat more forceful. You may not even feel particularly stressed in the moment. Low-grade, chronic anxiety can keep your nervous system slightly activated throughout the day, making you more likely to notice your heartbeat at rest, especially when lying down at night. Exercise, therapy, and treatment for anxiety or depression can all reduce palpitation frequency in people whose episodes are stress-driven.
Caffeine, Alcohol, and Nicotine
Caffeine gets blamed constantly for palpitations, but recent research paints a more nuanced picture. A Harvard-affiliated study found that people who consumed more caffeinated coffee, tea, or chocolate were no more likely to experience palpitations than those who consumed less. In moderation (up to about three cups of coffee per day), caffeine may even have cardiovascular benefits. However, some people are particularly sensitive to caffeine even at low doses, and drinking large amounts of energy drinks high in caffeine can, in rare cases, trigger actual arrhythmias.
Alcohol is a different story. It can directly trigger atrial fibrillation, the most common type of sustained irregular heart rhythm. Alcohol and certain foods like aged cheeses, cured meats, and dried fruit also contain tyramine, an amino acid that raises blood pressure and can cause palpitations. Nicotine is a straightforward stimulant that increases heart rate and makes palpitations more likely.
Hormonal Shifts
If you’re a woman experiencing palpitations around your period, during pregnancy, or in perimenopause, fluctuating hormone levels are a likely explanation. As many as 54% of women report heart palpitations during menopause. Big surges in estrogen and progesterone affect the heart’s electrical signaling and can produce racing, fluttering, or skipping sensations. It’s also common to feel palpitations at the same time as a hot flash. These episodes are typically harmless and tend to settle as hormone levels stabilize.
Low Electrolytes
Your heart’s electrical system depends on minerals like potassium and magnesium to generate each beat in the correct rhythm. Potassium, in particular, controls the electrical potential that fires nerve and muscle cells, including the heart. When potassium drops too low, you can develop skipped beats or an irregular heartbeat. Severe deficiency can lead to dangerous arrhythmias.
You don’t need to be severely depleted for this to matter. Dehydration, heavy sweating, vomiting, diarrhea, and certain medications (especially diuretics) can all lower your electrolyte levels enough to trigger noticeable palpitations. If your episodes seem to cluster around heavy exercise, illness, or poor hydration, this is worth investigating with a simple blood test.
Thyroid Problems
An overactive thyroid gland floods your body with thyroid hormone, which makes your heart beat harder and faster. It can also trigger atrial fibrillation. If your palpitations come alongside unexplained weight loss, heat intolerance, trembling hands, or feeling wired and restless, thyroid dysfunction is a strong possibility. A blood test can confirm or rule this out quickly.
Palpitations After Eating
Some people notice palpitations specifically after meals. This can happen because digestion diverts blood flow to your stomach and intestines, prompting your heart to compensate by beating faster. Large, heavy meals amplify this effect. Sugary foods that cause a rapid insulin spike, alcohol with a meal, or caffeine after eating can all layer additional triggers on top of the digestive response. Eating smaller meals and limiting stimulants around mealtimes often helps.
When Palpitations Point to a Heart Condition
A small percentage of palpitations do stem from an underlying rhythm disorder. The most common is atrial fibrillation, which affects more than 2.5 million Americans. During atrial fibrillation, the upper chambers of the heart fire chaotically at over 400 beats per minute, preventing the lower chambers from filling and pumping blood efficiently. This one matters because it raises stroke risk and often needs treatment.
Another possibility is paroxysmal supraventricular tachycardia (PSVT), which causes sudden episodes of rapid heartbeat due to a short circuit in the heart’s electrical wiring. PSVT tends to start and stop abruptly, can happen during vigorous exercise, and is most common in younger people. It’s usually not dangerous but can be very uncomfortable.
Symptoms That Need Emergency Attention
Most palpitations don’t require urgent care, but certain accompanying symptoms change the equation. Seek emergency attention if palpitations occur alongside chest pain or discomfort, fainting, severe shortness of breath, or severe dizziness. These combinations can signal a serious arrhythmia or another cardiac event that needs immediate evaluation.
How Palpitations Are Diagnosed
The challenge with diagnosing palpitations is that they’re often intermittent. Your heart may behave perfectly during an office visit, so doctors use a layered approach to catch the rhythm disturbance in the act.
The first step is usually an electrocardiogram (EKG), a painless test where electrodes placed on your chest record your heart’s electrical activity for about 10 seconds. If the EKG is normal but your symptoms continue, you may be given a Holter monitor, a portable device worn for a day or more that continuously records your heart rhythm during normal activities.
For palpitations that happen less than once a week, an event recorder is more practical. You wear it for up to 30 days and press a button when symptoms occur, capturing the exact rhythm at that moment. Your doctor may also order an echocardiogram, which uses ultrasound to create a moving image of your heart’s structure and blood flow. Blood tests for thyroid function, electrolytes, and iron levels round out the workup and can catch the most common non-cardiac causes in a single draw.
If you’re experiencing palpitations that are frequent, worsening, or accompanied by other symptoms, these tests can typically pinpoint or rule out a cause within a few weeks. For the majority of people, the answer turns out to be reassuring.