Why does my heart race when I lie down?

A racing heart, or palpitations, when you lie down is fairly common and is often harmless. It can happen because lying flat changes how you feel your heartbeat, or because something is triggering palpitations at bedtime.

Common reasons include:

• Body position changes: When you lie down, blood shifts in your body and your heartbeat can feel more noticeable.
• Being more aware at night: In a quiet room with fewer distractions, you may notice your normal heartbeat more clearly.
• Stress or anxiety: Bedtime is often when worries show up, and that can raise your heart rate.
• Reflux or a full stomach: Lying down after a large or late meal can worsen acid reflux and make you feel uncomfortable or notice palpitations.
• Caffeine, nicotine, alcohol, or heavy meals: These can trigger palpitations or make your body feel more “revved up,” especially near bedtime.
• Dehydration: Not drinking enough can make your heart beat faster, which may be more noticeable when you rest.
• Sleep apnea: If you wake up suddenly with a racing heart, especially with snoring or gasping, sleep apnea is one possible cause.

What you can try:

• Sleep with your head slightly elevated.
• Avoid caffeine, nicotine, alcohol, and large meals close to bedtime.
• Drink enough water during the day.
• Try slow breathing or relaxation exercises before bed.

Get medical help urgently if the racing heart comes with chest pain, shortness of breath, fainting, severe dizziness, or if it happens often, lasts a long time, or is getting worse.