What Makes The Lub Dub Sound [updated] | Trusted Source

🔊 → Your mitral & tricuspid valves close right after the heart squeezes blood to the lungs and body. This stops blood from flowing backward into the upper chambers.

👂 The pause between lub and dub? That’s your heart filling with blood. The pause after dub? That’s your heart resting before the next beat. what makes the lub dub sound

If you hear a whoosh or swish instead of a clean lub-dub, that’s called a heart murmur — often harmless, but worth getting checked out. 🔊 → Your mitral & tricuspid valves close