That weird feeling in your chest is most likely a heart palpitation, and it’s one of the most common reasons people search for heart-related symptoms online. Palpitations can show up as a racing, pounding, fluttering, or flip-flopping sensation, or it can feel like your heart skipped a beat or added an extra one. In most cases, the sensation is harmless and temporary. But understanding what’s behind it helps you figure out whether you can shrug it off or whether something else is going on.
What You’re Actually Feeling
The “weird” sensation usually comes from a premature heartbeat. Your heart’s electrical system fires a beat slightly earlier than expected, followed by a longer-than-normal pause before the next beat. That pause allows the heart to fill with a little extra blood, and the beat that follows feels unusually forceful. So the sensation isn’t really a skipped beat. It’s the stronger-than-usual beat right after one. These premature beats can originate in the upper chambers of the heart or the lower chambers, and both types are extremely common in healthy people.
Other times, the weird feeling comes from your heart genuinely speeding up. Your resting heart rate might jump from 70 to 120 or higher within seconds, creating a racing or pounding sensation in your chest, throat, or neck. This can happen from a burst of adrenaline, a sudden change in body position, or an underlying rhythm issue. The key distinction is between a heart that’s beating irregularly (skipping, adding beats) and one that’s beating fast but regularly. Both feel strange, but they point to different causes.
Common Triggers That Aren’t Heart Disease
Most palpitations trace back to something your body is reacting to rather than a structural heart problem. The most frequent triggers are lifestyle-related and reversible.
Caffeine and stimulants: Caffeine in normal amounts doesn’t increase the risk of dangerous rhythm problems for most people. But individual sensitivity varies widely. If you notice palpitations after coffee, energy drinks, or pre-workout supplements, you may simply be more reactive to stimulants than average. Nicotine and certain decongestant medications can have a similar effect.
Alcohol: Even moderate drinking makes the heart more susceptible to rhythm disturbances. Randomized trials have shown that people who abstain from alcohol are less likely to have recurring episodes of irregular heart rhythms than those who keep drinking. If palpitations are a regular occurrence for you, alcohol is one of the first things worth cutting back on.
Poor sleep and dehydration: Sleep deprivation raises your baseline stress hormone levels, which directly increases heart rate and makes premature beats more likely. Dehydration reduces blood volume, forcing the heart to work harder to maintain circulation. Both are easy to overlook and easy to fix.
Intense exercise: A hard workout can trigger premature beats during or after the session, especially if you’re dehydrated or underfueled. This is usually harmless, but palpitations that happen consistently during exertion deserve a closer look.
Anxiety and Your Heart
Anxiety is one of the most common causes of palpitations, and it creates a frustrating feedback loop: you feel anxious, your heart races, and then you feel more anxious because your heart is racing. The mechanism is straightforward. Anxiety activates your body’s fight-or-flight system, which floods your bloodstream with adrenaline. Your heart rate increases, your breathing quickens, and your chest muscles tighten. All of this can create a sensation that feels almost identical to a cardiac problem.
One useful distinction: palpitations from anxiety tend to start suddenly and resolve quickly, often within a few minutes. They typically coincide with a stressful moment, a worried thought, or a panic attack. Palpitations that happen frequently, last longer than a few minutes, or occur without any emotional trigger are less likely to be anxiety-related and more likely to have a cardiac or metabolic origin.
Hormonal and Metabolic Causes
Your thyroid gland has a direct line to your heart’s electrical system. An overactive thyroid pumps out excess hormone that makes the heart beat harder and faster, and it can trigger abnormal rhythms including atrial fibrillation, a chaotic quivering of the heart’s upper chambers. If your palpitations come with unexplained weight loss, heat intolerance, trembling hands, or unusual fatigue, a thyroid issue is worth investigating. A simple blood test can confirm or rule it out.
Hormonal shifts during menstruation, pregnancy, and perimenopause can also provoke palpitations. Fluctuating estrogen levels appear to affect the heart’s electrical stability, which is why many women notice palpitations for the first time in their 40s or 50s without any other cardiac risk factors.
Electrolyte imbalances play a role too. Magnesium and potassium are essential for maintaining a stable heart rhythm. Healthy magnesium levels fall between 1.46 and 2.68 mg/dL, and dropping below that range can cause rhythm disturbances. Severely low magnesium can trigger dangerous arrhythmias. Common causes of low magnesium include heavy alcohol use, chronic diarrhea, certain medications (particularly diuretics and acid-blocking drugs), and diets low in leafy greens, nuts, and whole grains.
When It Could Be a Rhythm Problem
A small percentage of palpitations come from a true arrhythmia, meaning the heart’s electrical system is misfiring in a sustained or organized way rather than just throwing an occasional extra beat. The most common types include atrial fibrillation (an irregular, often rapid rhythm in the upper chambers) and supraventricular tachycardia (sudden episodes of very fast but regular heartbeat that start and stop abruptly).
Premature ventricular contractions, or PVCs, fall somewhere in between. Nearly everyone has a few per day without noticing. Researchers generally consider fewer than 1,000 PVCs per day a low burden, while more than 15,000 to 20,000 per day is considered high. A high PVC burden sustained over months or years can, in rare cases, weaken the heart muscle. But the vast majority of people with occasional PVCs have nothing to worry about.
The distinction that matters most is how the palpitations behave. Benign premature beats come and go in isolated blips. They may happen a few times a day or a few times a week, and each episode lasts only a beat or two. Arrhythmias like atrial fibrillation tend to last minutes to hours and produce a sustained sensation of irregularity, sometimes accompanied by lightheadedness, shortness of breath, or unusual fatigue.
Tracking Your Symptoms
If palpitations happen regularly, tracking them gives you and your doctor far more to work with than a vague description. Note when they happen, how long they last, what you were doing, and what you consumed in the hours before. Patterns often emerge quickly: post-coffee, post-alcohol, during stressful meetings, or after poor sleep.
Consumer wearables have become surprisingly accurate at detecting rhythm problems. A recent meta-analysis found that smartphone-based detection tools identified atrial fibrillation with about 94% sensitivity and 96% specificity. The Fitbit Heart Study reported a positive predictive value of 98.2% for irregular pulse notifications. Samsung’s Galaxy Watch achieved 96.9% sensitivity when its optical sensor was combined with an on-demand ECG reading. These devices aren’t replacements for a medical evaluation, but an irregular rhythm captured on a wearable gives a clinician something concrete to review, which is far more useful than describing a sensation from memory.
Signs That Need Prompt Attention
Most palpitations are harmless. But certain combinations of symptoms suggest the heart isn’t pumping blood effectively, and those warrant urgent evaluation. Take palpitations seriously if they come with chest pain or pressure, fainting or near-fainting, significant shortness of breath, or severe dizziness that doesn’t pass quickly. Palpitations during exertion that force you to stop what you’re doing also fall into this category, as do episodes that last many minutes and don’t resolve on their own.
A palpitation that happens once while you’re sitting on the couch, lasts a second or two, and disappears is almost certainly a premature beat. A palpitation that lasts 10 minutes, makes you lightheaded, and happens repeatedly is telling you something different. The pattern, the duration, and what accompanies it matter far more than the sensation itself.