Why do I wake up with my heart racing?

Waking with your heart pounding is usually an adrenaline event: a vivid dream or nightmare you barely remember, a surge from the stress system that runs highest in early morning, a blood sugar dip overnight, alcohol from the evening wearing off, or sleep apnea - where a breathing pause triggers a fight-or-flight jolt that wakes you with a pounding heart and sometimes a gasp. Occasional episodes with a recognizable trigger are common and benign. The patterns that point at heart rhythm: waking with a racing heart that is very fast and very regular - like a metronome, often 150-plus - and that stops as suddenly as it started suggests SVT, a benign-but-worth-treating electrical loop. A racing heart that is chaotic and irregular, especially with dizziness or breathlessness, can be atrial fibrillation. NHLBI notes arrhythmias can produce racing, fluttering, or skipping sensations, and both patterns deserve an ECG - ideally captured during an episode, so mention it promptly and note the time it happens. Emergency version: racing heart with chest pain, fainting, severe breathlessness, or a heart rate that stays very fast without settling - call emergency services. For the recurring benign-looking kind: log episodes - time, duration, evening alcohol, stress - cut evening alcohol and late caffeine, treat any snoring or apnea suspicion seriously, and book the ECG conversation. Pymander is a free AI doctor, 24/7 by text. Describe the episodes and their timing, and it can help you sort adrenaline from arrhythmia.