Anxiety causes heart palpitations by triggering your body’s stress response, which floods your heart with stimulating hormones that make it beat harder, faster, and sometimes irregularly. This is one of the most common physical symptoms of anxiety, and in most cases it’s harmless, even though it can feel alarming enough to make the anxiety worse.
The Stress Response and Your Heart
When you feel anxious, your brain interprets the situation as a potential threat and activates the sympathetic nervous system, the branch responsible for your fight-or-flight response. This sets off a chain reaction: your brain sends signals through the neurotransmitter norepinephrine (noradrenaline) to your adrenal glands, which then release both adrenaline and noradrenaline into your bloodstream.
These stress hormones act directly on your heart. They make it pump harder and faster to deliver more oxygenated blood to your muscles, preparing you to fight or run. Your blood pressure rises. Your heart rate increases. In a genuine emergency, this would be useful. During a work meeting or while lying in bed at 2 a.m., it just feels like your heart is pounding out of your chest.
The problem is that your body doesn’t distinguish between a real physical threat and the kind of worry that comes from thinking about your finances or replaying an awkward conversation. The hormonal cascade is the same either way, and your heart responds identically to both.
Why You Feel Skipped or Extra Beats
Palpitations from anxiety don’t always feel like a fast heartbeat. Many people describe a fluttering sensation, a feeling that the heart “skipped a beat,” or a single hard thump. These sensations often come from premature contractions, which are extra heartbeats that originate slightly earlier than your normal rhythm.
These premature beats can start in your heart’s upper chambers (premature atrial contractions, or PACs) or lower chambers (premature ventricular contractions, or PVCs). After the premature beat, there’s usually a brief pause before the next normal beat. That next beat is more forceful than usual because the heart had an extra moment to fill with blood. That forceful thump is what you actually feel, not the premature beat itself.
Sympathetic nervous system activation, the kind that anxiety triggers, is directly linked to these premature contractions. The surge of stress hormones increases the electrical excitability of heart cells, making it easier for stray electrical signals to fire and produce extra beats. In a healthy heart, these are almost always benign. They’re incredibly common even in people without anxiety, but stress and anxiety make them more frequent and more noticeable.
How Breathing Patterns Make It Worse
Anxiety often changes the way you breathe without you realizing it. Many people hyperventilate during anxious episodes, taking rapid, shallow breaths that blow off too much carbon dioxide. This drops carbon dioxide levels in your blood, a state called respiratory alkalosis, which causes blood vessels to constrict, including those supplying your brain.
That constriction produces dizziness, a pounding heartbeat, and a feeling of breathlessness, all of which can mimic or amplify the sensation of palpitations. The breathlessness then reinforces the anxiety (“something must be wrong with my heart”), which drives more hyperventilation, creating a feedback loop that can escalate into a full panic attack. Many people who experience palpitations during anxiety are actually feeling the combined effects of stress hormones and disrupted breathing, not just one or the other.
The Anxiety-Palpitation Feedback Loop
One of the most frustrating aspects of anxiety-related palpitations is that noticing them tends to make them worse. You feel an unusual heartbeat, which triggers a spike in anxiety, which releases more stress hormones, which produces more palpitations. Your attention narrows onto your chest, and suddenly you’re hyper-aware of every beat. Normal variations in heart rhythm that you’d never notice on a calm day become deeply unsettling.
This cycle explains why palpitations often happen at rest, particularly at night. When you’re busy or distracted, you simply don’t notice mild rhythm changes. When you’re lying in a quiet room with nothing to focus on, every heartbeat becomes audible and every irregularity feels significant.
Red Flags Worth Knowing About
Most anxiety-related palpitations are harmless, but certain accompanying symptoms suggest something beyond anxiety may be going on. Sudden collapse or loss of consciousness warrants an immediate trip to the emergency room. The same is true if a racing heart comes with significant dizziness or lightheadedness, or if you’re experiencing chest pain alongside the palpitations.
Family history matters too. If a close relative experienced sudden cardiac death at a young age or was diagnosed with an inherited heart condition, palpitations deserve a more thorough workup. Young people with these family histories are a particular concern, because certain genetic heart rhythm disorders first show up during periods of physical or emotional stress.
How Doctors Tell the Difference
Distinguishing anxiety-driven palpitations from a heart rhythm problem requires catching the irregular beat on a recording. A standard electrocardiogram (ECG) captures your heart’s electrical activity, but only for a few seconds. Since palpitations come and go, a single ECG often misses them entirely.
For that reason, doctors often use portable monitors. A Holter monitor is a small device you wear for 24 to 48 hours with electrodes attached to your chest, recording every heartbeat continuously. If your palpitations are less frequent, an event monitor records for about a month. You carry it with you and press a button whenever you feel an irregular beat, so the recording captures exactly what your heart is doing at that moment. The goal is to match your symptoms to a specific rhythm on the recording. If the monitor shows a normal rhythm during the moments you feel palpitations, that’s strong evidence that anxiety is the driver.
Physical Techniques That Slow Your Heart
When palpitations hit, there are physical maneuvers that activate your vagus nerve, which acts as a brake on your heart rate. These techniques work by stimulating the parasympathetic nervous system, the counterpart to the fight-or-flight system, and they can slow down a fast heart rhythm 20% to 40% of the time.
The most well-known is the Valsalva maneuver: lie on your back, take a deep breath, then try to exhale forcefully with your mouth and nose closed for 10 to 30 seconds. It should feel like trying to blow air through a blocked straw. Another option is the diving reflex. Take several deep breaths while sitting, hold the last one, and submerge your face in a container of ice water for as long as you can tolerate it. If that’s impractical, pressing a bag of ice or an ice-cold wet towel firmly against your face triggers a similar response. Even forceful coughing can activate the vagus nerve enough to interrupt a fast rhythm.
These techniques are most effective for heart rates above 100 beats per minute caused by supraventricular tachycardia, a type of fast rhythm originating in the upper chambers. For the milder palpitations that anxiety typically produces, they can still help by shifting your nervous system away from its stressed state. Slow, deliberate breathing on its own, even without a formal maneuver, counteracts the hyperventilation component and helps break the feedback loop between anxiety and your heart.