That unsettling flutter or “skipped beat” feeling is almost always caused by a premature heartbeat, a contraction that fires slightly earlier than it should. These extra beats are extremely common in healthy people, and the sensation you notice is usually not the early beat itself but what happens right after it. The pause following a premature beat gives your heart extra time to fill with blood, so the next normal beat is stronger than usual. That forceful thump is what most people actually feel, often described as a flip-flop, a pause, or the heart momentarily stopping.
What Actually Happens Inside Your Heart
Your heart runs on a precise electrical system. A natural pacemaker at the top of the heart sends a signal that travels through specific pathways, telling each chamber when to contract. A premature beat occurs when a spot outside that normal pacemaker fires off its own electrical impulse ahead of schedule. This can happen in the upper chambers (called premature atrial contractions) or the lower chambers (premature ventricular contractions, or PVCs).
The exact reason a heart cell fires early isn’t fully understood, but researchers at the American Heart Association have identified three general mechanisms. Sometimes a buildup of calcium inside a heart cell triggers an extra signal. Other times, individual heart cells that normally sit quietly develop their own low-level rhythmic firing, essentially becoming tiny rogue pacemakers. In rarer cases, an electrical signal gets caught in a loop, traveling around a small patch of scar tissue or damaged cells and re-entering the healthy tissue at the wrong time.
Regardless of which mechanism is at play, the result feels the same: a brief interruption in your heart’s rhythm, followed by a noticeably hard beat as the heart compensates.
Common Triggers
Several everyday factors can increase the frequency of premature beats. Stress and anxiety top the list because they raise levels of adrenaline, which makes heart cells more excitable. Poor sleep, dehydration, and intense exercise can have a similar effect.
Alcohol is one of the most consistently demonstrated triggers. A 2021 UCSF clinical trial that tracked real-time heart rhythms using wearable monitors found that alcohol consumption was the only trigger that reliably and significantly increased episodes of irregular rhythm. Caffeine, by contrast, showed no such relationship. In fact, UCSF researchers found caffeine may even have a mildly protective effect on heart rhythm, contradicting a widespread belief that coffee causes palpitations.
Other common triggers include nicotine, certain decongestants and stimulant medications, and eating very large meals (which can stimulate the vagus nerve running near the heart).
The Role of Electrolytes
Your heart’s electrical system depends on minerals like potassium and magnesium moving in and out of cells at precisely the right moments. These movements create the voltage changes that power each heartbeat. When potassium levels drop too low, those voltage changes become erratic, and skipped or irregular beats are one of the earliest symptoms. Low magnesium makes the problem worse because magnesium helps your body retain potassium. A deficiency in one often leads to a deficiency in the other.
You don’t need a dramatic deficiency for this to matter. Heavy sweating, chronic diarrhea, certain blood pressure medications, and diets very low in fruits and vegetables can all push these minerals low enough to increase premature beats.
Why Menopause Makes It Worse
Hormonal changes are a major and often overlooked trigger. Estrogen helps regulate heart rate by promoting the branch of the nervous system that keeps the heart calm and steady while dampening the branch that speeds it up. As estrogen declines during perimenopause and menopause, that balance shifts.
The numbers are striking: up to 42% of perimenopausal women and 54% of postmenopausal women report palpitations. About 16% of women experience frequent palpitations during perimenopause and early postmenopause, while another 34% have them at a moderate level. For most women, the frequency decreases over time as the body adjusts, but the sensation can be alarming when it’s new. Postmenopausal women also tend to have higher resting heart rates and less beat-to-beat variability in their heart rhythm compared to premenopausal women, both signs of reduced cardiovascular flexibility.
When Skipped Beats Are Harmless
For the vast majority of people, occasional premature beats are a normal part of how the heart works. Nearly everyone has them if monitored long enough. They come and go, often clustering during periods of stress or fatigue, and they don’t damage the heart or shorten your life.
The threshold where premature beats start to matter is surprisingly high. Research from the University of Arizona’s Sarver Heart Center indicates that only when PVCs account for more than 20 to 40% of all heartbeats does the sheer volume of extra contractions risk weakening the heart muscle over time. For context, that means thousands of extra beats every hour, not the handful of flip-flops you notice at bedtime. Even in those rare cases, the weakening can often be reversed once the extra beats are brought under control.
Signs That Need Attention
Certain accompanying symptoms point to something more serious than a benign premature beat. These include fainting or near-fainting (especially if you injure yourself falling), chest pain, significant shortness of breath, and palpitations that consistently happen during exercise rather than at rest. A resting heart rate above 120 or below 45 beats per minute also warrants evaluation, as does a family history of sudden cardiac death or unexplained fainting.
The pattern matters too. An isolated skip now and then is very different from a new, sustained irregular rhythm that doesn’t resolve on its own. If your heartbeat suddenly feels chaotic and stays that way for minutes, that’s a different situation than the occasional thud.
How Skipped Beats Are Evaluated
If your skipped beats are frequent or bothersome enough to investigate, the standard first step is a Holter monitor, a small wearable device that continuously records your heart’s electrical activity, typically for one to two days. It captures every single beat, including premature ones you may not even feel, and calculates what percentage of your total heartbeats are abnormal.
Because skipped beats can be unpredictable, a day or two of monitoring sometimes isn’t enough to catch them. In that case, an event monitor can be worn for several weeks. You press a button when you feel symptoms, and the device saves a recording of what your heart was doing at that moment. This approach is especially useful for people who have palpitations only a few times a week.
Reducing Premature Beats on Your Own
Since most skipped beats are benign and driven by triggers, the most effective approach is identifying and managing those triggers. Cutting back on alcohol is the single best-supported lifestyle change. Managing stress through regular physical activity, adequate sleep, and breathing techniques can lower the adrenaline surges that make heart cells fire early. Staying well-hydrated and eating potassium-rich foods like bananas, potatoes, and leafy greens supports the electrical stability of heart cells.
Many people find that simply understanding the mechanism makes the sensation less frightening. Anxiety about palpitations creates a feedback loop: the skip triggers a surge of worry, which triggers more adrenaline, which triggers more skips. Knowing that the strong beat you feel is just your heart working exactly as it should, compensating for a brief pause, can break that cycle.