Overview

• An international team reported the findings in Science Advances using laboratory simulations of normal and deep breaths.
• Deep breaths caused a pronounced drop in the surface tension of pulmonary surfactant compared with regular breathing.
• Researchers point to a multilayer architecture with a stiffer top layer over softer layers that deep breaths help reestablish.
• Saturated lipids concentrated at the air–liquid interface during deep breaths, creating denser packing that lowers tension.
• The mechanism explains the common sense of relief after a sigh and suggests preliminary avenues for future surfactant-based therapies.