What is the physiological sigh

The physiological sigh is two inhales followed by one long exhale—a breathing pattern that can quickly reduce stress and promote calm. 1

• 1. Double inhale: Take a deep inhale, then a second smaller inhale. The second breath helps reinflate small air sacs (alveoli) in the lungs. 1
• 2. Long exhale: Exhale slowly and fully. The extended exhale helps clear carbon dioxide and relaxes you quickly. 1
• 3. Natural and intentional: This sigh happens spontaneously during wakefulness and sleep, and you can also deliberately use it when stressed. 2

In short: double inhale, long exhale.