A sudden awareness of your own heartbeat, racing, pounding, fluttering, or seeming to skip, can be startling even when nothing is actually wrong. Palpitations are best understood as a symptom, not a diagnosis in themselves, and the range of things that can cause them runs from entirely harmless, everyday triggers to genuine heart rhythm conditions that need treatment.
Why This Sensation Is So Common and Usually So Harmless
Palpitations are generally defined as an increased awareness of your own heartbeat, and they can be caused by the heart beating faster, slower, or more forcefully than usual, or simply by heightened attention to a normal heartbeat during a moment of stress or stillness. Common, everyday triggers include strong emotions like stress, anxiety, or excitement, physical exertion, caffeine, nicotine, and certain medications, including some decongestants and stimulant medications. In many cases, despite feeling alarming in the moment, an evaluation finds an entirely normal heart rhythm underneath.
What Sometimes Lies Behind a More Concerning Case
Less commonly, palpitations reflect an actual abnormal heart rhythm, called an arrhythmia, where the heart’s electrical signaling is genuinely disrupted rather than simply responding to a temporary trigger. Certain medical conditions unrelated to the heart’s electrical system can also cause palpitations, including an overactive thyroid, anemia, low blood sugar, and imbalances in the body’s salts, called electrolytes. This is part of why an evaluation for persistent or concerning palpitations often includes blood tests alongside tests that look directly at heart rhythm.
Making Sense of Why Diagnosis Can Be Tricky
One of the more frustrating aspects of investigating palpitations is that the episode itself is often brief and unpredictable, meaning it can be entirely over by the time a person reaches a doctor’s office. An ECG, described in its own article elsewhere in the DiagnoseWise library, only captures the heart’s electrical activity at the exact moment it is performed, so a single ECG taken between episodes may show a perfectly normal rhythm even when palpitations are a genuine, recurring problem. This is exactly why doctors often recommend extended heart rhythm monitoring, sometimes for a day, a week, or longer, specifically to catch an episode as it happens rather than relying on a single brief snapshot.
Making Sense of How the Episode Actually Felt
Details about how a palpitation episode felt, and what was happening at the time, matter considerably for narrowing down a cause. How long did it last, seconds, minutes, or longer? Did it start and stop suddenly, or build and fade gradually? Was it triggered by exercise, caffeine, stress, or nothing identifiable at all? These details, though they may feel vague in the moment, give a doctor considerably more to work with than a general description of “my heart was racing.”
The Signs That Mean It Is an Emergency
Palpitations that occur alongside chest pain, severe shortness of breath, fainting, or significant dizziness should be treated as a possible emergency, warranting immediate medical attention rather than waiting to see if the episode passes. Palpitations in someone with a known history of heart disease, or episodes that are becoming more frequent or more severe over time, are also worth discussing with a doctor promptly, even without these more dramatic accompanying features.
The Question Worth Asking Yourself
If you experience palpitations, the most useful question is rarely “how fast did my heart feel like it was going?” A more useful question is “did anything else happen alongside it, chest pain, dizziness, or shortness of breath?” That question reflects the details that actually determine how urgently palpitations need to be evaluated, since the sensation alone, however alarming, rarely tells the full story on its own.