Recurring heart palpitations are usually caused by premature heartbeats, which are extra beats that start in the wrong part of the heart and fire sooner than expected. These are extremely common and, in most cases, harmless. But “usually harmless” isn’t the same as “always harmless,” and the fact that yours keep happening is a reasonable thing to investigate. The cause is almost always one of a handful of triggers: stimulants, stress, hormonal shifts, or an underlying condition that’s making your heart’s electrical system irritable.
What’s Actually Happening in Your Heart
Your heart has a built-in pacemaker in its upper chambers that sends a rhythmic electrical signal to keep everything beating in order. Palpitations happen when a rogue electrical signal fires from somewhere else, usually the lower chambers, before the next scheduled beat. These premature contractions make the heart feel like it’s skipping, fluttering, or pounding. The “thud” you notice is often the beat after the early one, which is stronger than normal because the heart had a split second longer to fill with blood.
Heart disease, scarring, or changes in the body’s chemistry can make the cells in the lower chambers electrically unstable, causing these signals to misfire more frequently. But in many people, there’s no structural problem at all. The misfiring is triggered by something external.
Common Triggers That Set Off Palpitations
Caffeine, Nicotine, and Alcohol
Caffeine and nicotine are both stimulants that ramp up the nervous system’s excitatory signals while blocking the brain’s natural calming chemical, adenosine. The result is a heart that beats faster and is more prone to premature beats. You don’t have to drink a lot of coffee for this to happen. Some people are simply more sensitive, and sensitivity can change over time, which is why a habit you’ve had for years might suddenly start causing problems.
Alcohol works differently. It suppresses the signaling chemicals involved in attention and motor control, but it also irritates the heart muscle directly. Even moderate drinking can trigger episodes of irregular rhythm, sometimes called “holiday heart” because it often shows up after a night of heavier than usual intake.
Stress and Anxiety
Mental stress activates a very targeted response in the body. Research shows that during psychological stress, the brain sends a concentrated burst of nervous system activity specifically to the heart while largely sparing other areas like the muscles in your arms and legs. At the same time, the adrenal glands release adrenaline into the bloodstream. This combination speeds up the heart rate and makes it more susceptible to irregular beats.
In people with anxiety or panic disorder, this system can become chronically overactive. The sympathetic nerves that supply the heart start firing in rapid multiple bursts within a single heartbeat cycle, and the chemical signals they release aren’t properly cleared away afterward. This creates a feedback loop where the heart stays in a heightened state of electrical excitability even when no immediate threat exists. If you notice your palpitations cluster around stressful periods or moments of worry, this mechanism is likely involved.
Sleep Deprivation and Dehydration
Poor sleep raises baseline stress hormones, which keeps your heart in that same excitable state described above. Dehydration reduces your blood volume, forcing the heart to beat faster to maintain circulation. Both are easy to overlook as causes because they don’t feel dramatic, but they’re among the most common reasons palpitations become persistent.
Hormonal Causes, Especially in Women
As many as 54% of women report heart palpitations during menopause. Fluctuating hormone levels are one of the most common explanations. Big surges in estrogen and progesterone during pregnancy, around menstruation, or during perimenopause can make the heart more sensitive to its own electrical signals. Palpitations often coincide with hot flashes, arriving at the same moment as that sudden wave of heat.
If your palpitations seem to follow a monthly pattern or started around the time of other menopausal symptoms, hormonal shifts are a strong candidate. These episodes are typically benign, but they can feel alarming, especially when they’re new.
Medical Conditions Worth Ruling Out
Several treatable conditions cause persistent palpitations, and your doctor will likely check for them with basic blood work.
- Hyperthyroidism: An overactive thyroid floods the body with hormones that speed up the metabolism and the heart. A simple blood test measuring thyroid-stimulating hormone (TSH) is enough to flag the problem. Palpitations from hyperthyroidism usually come alongside tremor, heat intolerance, unexplained weight loss, and nervousness.
- Anemia: When your blood can’t carry enough oxygen, the heart compensates by beating faster and harder. Low iron is the most common cause, and it’s especially worth considering if you also feel unusually tired or short of breath.
- POTS (Postural Orthostatic Tachycardia Syndrome): This condition causes an abnormal heart rate jump when you stand up. The diagnostic threshold is an increase of at least 30 beats per minute within the first 10 minutes of standing (40 bpm in adolescents). POTS has become more widely recognized in recent years, partly because it can develop after viral infections. If your palpitations are worst when you stand up or change position, this is worth discussing with a doctor.
How Doctors Figure Out the Cause
The challenge with palpitations is that they often don’t happen during a standard office visit or a quick EKG. If the initial EKG is normal, the next step is usually some form of extended monitoring. The options cover a wide range of timelines:
- Holter monitor: Records your heart rhythm continuously for 24 to 48 hours. Good if your palpitations happen at least daily.
- Patch recorder: Sticks to your chest and monitors nonstop for up to two weeks.
- Cardiac event monitor: Records your heart rate and rhythm for up to a month. You press a button when you feel symptoms, and it captures the electrical activity around that moment.
- Implanted loop recorder: A small device placed under the skin that monitors for multiple years. This is reserved for cases where episodes are infrequent but concerning.
The goal is to catch your heart in the act so your doctor can see exactly what type of rhythm disturbance is occurring, if any. Many people go through monitoring only to find that what they’re feeling is benign premature beats, which is genuinely reassuring information.
When Palpitations Signal Something Serious
Most palpitations are not dangerous, but certain combinations of symptoms change the picture. Palpitations that come with dizziness, near-fainting, or actual fainting suggest a fast abnormal rhythm that’s briefly cutting off adequate blood flow to the brain. These episodes need prompt evaluation.
Other warning signs include chest pain or pressure during the palpitations, palpitations that last several minutes without letting up, and episodes that happen during exertion rather than at rest. A resting heart rate consistently above 100 beats per minute also warrants investigation. If your palpitations are brief, happen at rest, and resolve on their own without any of these features, the odds strongly favor a benign cause.
Reducing Palpitations on Your Own
If your palpitations are tied to lifestyle triggers, the fix is often straightforward. Cutting back on caffeine is the most common first step, and it doesn’t have to mean zero coffee. Try halving your intake for two weeks and see if the frequency drops. The same applies to alcohol, especially if your episodes tend to follow evenings when you drink.
For stress-driven palpitations, anything that dials down sympathetic nervous system activity helps. Slow breathing exercises, where you extend the exhale longer than the inhale, directly activate the calming branch of the nervous system that opposes the fight-or-flight response. Regular aerobic exercise has a similar effect over time by resetting baseline nervous system tone. Consistent sleep of seven or more hours matters more than most people expect.
Staying well hydrated and maintaining adequate electrolyte intake, particularly magnesium and potassium, supports stable electrical signaling in the heart. Electrolyte imbalances from heavy sweating, restrictive diets, or chronic dehydration are an underappreciated trigger for premature beats.