Lifestyle

5 Warning Signs Your Heart Rhythm May Be Off That Cardiologists Say Most People Ignore

By Erica Coleman · July 28, 2026

Your heart is racing, your chest feels tight, and your palms are sweating. It feels like anxiety. It might not be.

Atrial fibrillation — the most common type of irregular heartbeat — shares so many symptoms with panic attacks that millions of Americans may be living with the condition without knowing it. An estimated 2.7 to 6.1 million people in the United States have AFib, and a person with untreated AFib is five times more likely to have a stroke than someone without it. The condition can also lead to heart failure.

The overlap with anxiety is what makes it dangerous. Here’s what cardiologists say to watch for.

Your heart doesn’t just race — it feels irregular. Anxiety speeds up your heart rate, but the rhythm stays regular. AFib produces a distinctly irregular pattern — fluttering, skipping, or a sensation that your heart is stumbling over itself. If you can feel your pulse and it seems erratic rather than just fast, that’s a critical distinction.

The episodes happen when you’re calm or asleep. Anxiety-driven palpitations are typically triggered by stress and ease when you relax, breathe deeply, or distract yourself. AFib episodes can strike at random — even when you’re sitting quietly or sleeping. If your heart starts racing for no apparent emotional reason, the cause may be electrical, not psychological.

You feel unusually tired after ordinary activity. Fatigue that seems disproportionate to what you’re doing — climbing one flight of stairs and needing to sit down, or feeling wiped out after a short walk — can signal that your heart isn’t pumping efficiently. AFib reduces the heart’s ability to move blood, which means your body works harder to do less.

You get dizzy or lightheaded without a clear reason. Both anxiety and AFib can cause dizziness, but AFib-related lightheadedness often comes with no emotional trigger at all. It may happen mid-conversation, while standing still, or during routine tasks. Unexplained dizziness that recurs is worth a cardiology workup, not a prescription for anti-anxiety medication.

The episodes last longer than a panic attack should. A typical panic attack peaks within 10 minutes and resolves within 30. AFib episodes can last hours or even days. If your racing heart, chest tightness, or shortness of breath persists well beyond the window a panic attack would explain, the mechanism may be your heart’s electrical system rather than your nervous system.

The risk rises with age. AFib is most common in people over 65, and the likelihood increases with high blood pressure, obesity, diabetes, and heavy alcohol use. Women are more likely than men to be symptomatic. And because so many early episodes are brief and self-resolving, people often write them off for years before a longer or more severe episode finally sends them to a doctor.

The diagnostic test is a simple electrocardiogram. If episodes are intermittent, a portable heart monitor worn for a few days or weeks can catch what a single office visit might miss. The difference between an anxiety diagnosis and an AFib diagnosis can be the difference between a breathing exercise and a blood thinner — and that distinction matters.