Heart palpitations feel like your heart is pounding, fluttering, or skipping a beat. They’re extremely common, and most of the time they’re harmless. The list of potential triggers is long, ranging from your morning coffee to an overactive thyroid, so understanding the most likely culprits can help you figure out what’s going on in your case.
Caffeine, Alcohol, and Other Dietary Triggers
What you eat and drink is one of the most common and controllable causes of palpitations. Caffeine gets the most attention, though recent evidence suggests moderate intake (up to about three cups of coffee a day) is generally fine for your heart. Beyond that threshold, or if you happen to be particularly sensitive, even a single cup can set off a noticeable flutter.
Alcohol is another frequent offender. Even moderate drinking can trigger episodes of atrial fibrillation, a type of irregular heartbeat. High-sugar and high-carbohydrate foods can also cause palpitations by spiking your blood sugar, especially if you’re prone to low blood sugar episodes. Spicy and rich foods sometimes contribute indirectly by causing acid reflux, which can mimic or provoke a racing heart.
A few specific food compounds are worth knowing about:
- Tyramine, found in aged cheeses, cured meats, dried fruit, and alcohol, can raise blood pressure and trigger palpitations.
- Theobromine, the stimulant naturally present in chocolate, can increase heart rate.
- MSG, used as a flavor enhancer in processed foods and some restaurant meals, causes palpitations in people who are sensitive to it.
Dehydration and low potassium levels are two other dietary gaps that directly affect heart rhythm. If you’re not drinking enough water or eating potassium-rich foods like bananas, potatoes, and leafy greens, your heart’s electrical system may not fire as smoothly.
Stress, Anxiety, and Sleep
Your nervous system has a direct line to your heart rate. When you’re anxious or stressed, your body releases adrenaline, which speeds up your heartbeat and can make it feel like it’s pounding out of your chest. This can happen before, during, or after stressful situations, including something as routine as a tense meal. Many people first notice palpitations during periods of high stress and assume something is wrong with their heart, when the real driver is their stress response.
Poor sleep and exhaustion amplify this effect. When you’re running on too little rest, your body stays in a heightened state of alertness that makes palpitations more likely. Nicotine from cigarettes or vaping products is a stimulant that works through a similar mechanism, raising your heart rate and making irregular beats more noticeable.
Hormonal Changes
Fluctuating hormone levels are one of the most common causes of palpitations in women, particularly during menopause, pregnancy, and the days around a menstrual period. Big surges in estrogen and progesterone can make the heart more reactive. During menopause, palpitations frequently coincide with hot flashes, with many women feeling their heart race at the same time their face and chest flush with heat.
These hormone-driven palpitations are typically harmless, but they can be unsettling if you don’t know what’s causing them. If you notice a pattern that tracks with your cycle or with other menopausal symptoms, hormonal shifts are a likely explanation.
Thyroid Problems
Your thyroid gland acts as your body’s metabolic thermostat, and when it’s overactive (hyperthyroidism), it pushes your heart to beat faster and harder. Palpitations are one of the hallmark symptoms. An underactive thyroid can also play a role, sometimes causing anemia that in turn stresses the heart.
A simple blood test measuring thyroid-stimulating hormone (TSH) can reveal whether your thyroid is the issue. In hyperthyroidism, TSH drops to very low levels because the thyroid is producing too much hormone on its own. If your palpitations come with unexplained weight changes, heat intolerance, or unusual fatigue, a thyroid check is a reasonable first step.
Anemia and Iron Deficiency
When your red blood cell count is low, your heart has to pump harder and faster to deliver enough oxygen throughout your body. This extra workload often shows up as palpitations, especially during physical activity or when climbing stairs. Iron deficiency is the most common nutritional cause of anemia, and it’s particularly prevalent in women with heavy periods, pregnant women, and people on restricted diets.
Medications and Supplements
Several common over-the-counter and prescription medications can trigger palpitations as a side effect. Decongestants are among the worst offenders. Cold and allergy products that contain pseudoephedrine (often labeled with a “D” after the brand name) can abnormally stimulate the heart and blood vessels, causing increased heart rate, higher blood pressure, or skipped beats. If you have any existing heart condition, these products carry extra risk.
Other medication categories linked to palpitations include asthma inhalers, diet pills, some antibiotics, thyroid medications, and insulin. Certain herbal supplements can also be triggers, including bitter orange (taken for heartburn or weight loss), ephedra (used for energy and colds), ginseng, and valerian. Just because something is sold over the counter or marketed as “natural” doesn’t mean it’s gentle on your heart.
Heart Rhythm Disorders
Sometimes palpitations signal an actual change in your heart’s electrical rhythm. The most common types include premature beats (extra beats that feel like a skip or a thud), supraventricular tachycardia (sudden episodes of rapid heartbeat originating above the lower chambers), and atrial fibrillation.
Atrial fibrillation, or AFib, is the most well-known arrhythmia. It happens when the heart’s upper chambers fire chaotic electrical signals instead of beating in a coordinated pattern. During an episode, heart rate can climb anywhere from 100 to 175 beats per minute. Along with palpitations, AFib can cause fatigue, dizziness, shortness of breath, and reduced exercise tolerance. Some people with AFib feel nothing at all, which is part of what makes it tricky to catch.
Premature beats are far more common and almost always benign. They feel like a skipped beat or a sudden thump, often followed by a brief pause. Most people experience them occasionally without any underlying heart disease.
Red Flags That Need Urgent Attention
Most palpitations pass on their own and don’t indicate anything dangerous. But certain accompanying symptoms change the picture. A sudden collapse or loss of consciousness during palpitations requires emergency care. The same goes for palpitations combined with dizziness, lightheadedness, or chest pain. A heart that races unexpectedly and won’t slow down, particularly if you feel faint, is another signal to get evaluated immediately.
How Palpitations Are Diagnosed
Figuring out the cause starts with a physical exam and a conversation about your medical history, medications, and diet. Your doctor will likely check for signs of conditions like thyroid disease or anemia.
If there’s concern about an underlying heart rhythm issue, the first test is usually an electrocardiogram (ECG), which records your heart’s electrical activity in real time. The catch is that palpitations are often intermittent, so a standard ECG taken in a clinic might look perfectly normal if your heart happens to be behaving at that moment.
For palpitations that come and go, a portable monitor worn at home is more useful. A Holter monitor records continuously for a day or more while you go about your normal activities. For symptoms that are even less frequent, an event recorder can be worn for up to 30 days. You press a button when you feel palpitations, and the device captures the heart’s rhythm at that exact moment. In some cases, an echocardiogram (an ultrasound of the heart) is ordered to check the heart’s structure and blood flow for any underlying problems.
Keeping a log of when your palpitations occur, what you ate or drank beforehand, how much sleep you got, and what your stress level was can make it much easier for you and your doctor to identify a pattern and pinpoint the cause.