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Glossary · S

Sleep rebound

What it means, when you'll hear it, and what it actually changes in practice.

Written & reviewed by Lisa Adair — IBCLC, paediatric sleep consultant & registered NICU nurse · Last reviewed 19 June 2026

Sleep rebound is the body's tendency to sleep longer or more deeply than usual after a period of sleep deprivation.

Sleep rebound describes what happens when, after a period of insufficient sleep, the body sleeps longer or more deeply than normal once it has the opportunity to recover. It reflects the way sleep pressure builds up while sleep is missed.

Why does it happen?

The drive to sleep is partly governed by a build-up of sleep pressure during waking hours. When sleep is repeatedly cut short, that pressure accumulates, and the body compensates at the next opportunity with deeper or longer sleep — a self-correcting mechanism that helps recover lost rest.

What does it look like in babies?

In infants and young children, a rebound can appear as an unusually long nap or a longer overnight stretch following a period of disrupted sleep — for example after illness, travel or several difficult nights. It is generally a sign of the body catching up, rather than a problem in itself.

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