What happens to your breathing while you sleep

In this story

• Why it matters
• Breathing changes with every stage
• Why you stop moving during dreams
• Snoring sits on a spectrum
• Restlessness is not always about the body
• Try this tonight
• Sources

While you sleep your body goes through a steady series of changes. Breathing slows and settles, then turns irregular. Muscles relax, then go slack entirely. You shift position, settle, and shift again.

None of it is random. Each change is tied to where you are in the sleep cycle.

Why it matters

Breathing that looks strange is often a normal part of the night. Knowing what is normal makes it easier to spot what is worth raising with a doctor.

Breaking down the science

Breathing changes with every stage

Respiration changes measurably with sleep state, and the clearest documented shift happens in REM. Ventilation becomes faster and more erratic during REM than in NREM sleep, varying from one breath to the next. That is not a fault. It is the signature of an active brain paired with a body that has gone still.

The body's safety mechanisms also loosen. The ventilatory response to low oxygen is already lower in NREM sleep than in wakefulness, and it falls further during REM, so the reflex that would normally prompt harder breathing is blunted at exactly the point breathing is least regular.

Why you stop moving during dreams

During REM the skeletal muscles are atonic and without movement, with the eyes and the diaphragmatic muscles as the documented exceptions.^[2] That is why you keep breathing and your eyes move under closed lids while the rest of you stays put.

Stillness during REM is therefore not the same as stillness during deep sleep. One is muscular shutdown, the other is simply a body at rest. From outside they look alike. Physiologically they are different states.

Snoring sits on a spectrum

Snoring is soft tissue vibrating as air moves through a narrowed upper airway.^[3] Throat muscle tone relaxes naturally during sleep, and for many people the resulting narrowing is mild and harmless.

But it is a spectrum. Loud, chronic snoring, particularly with gasping, choking or pauses in breathing, can indicate sleep-disordered breathing, which is a medical condition requiring evaluation. No app or article can diagnose it. If that description sounds familiar, the next step is a conversation with a clinician.

Restlessness is not always about the body

Movement and environment are more connected than people expect. A bedroom that runs warm interferes with the body's ability to shed heat, and thermal discomfort is among the most common causes of tossing and surfacing out of deep sleep.^[4] The body does not announce the problem. It just keeps looking for a comfortable position.

Restlessness might mean stress. It might mean a lighter stage. Or it might mean the room is two degrees too warm.

Try this tonight

• If you are restless, check the room first. A warm bedroom makes it harder to shed heat.
• If loud snoring comes with gasping, choking or pauses in breathing, talk to a doctor.

This article is general education, not medical advice. If you are worried about your sleep, talk to a doctor.

Sources

1. 1.Institute of Medicine; Colten HR, Altevogt BM, editors (2006). Sleep Physiology, in Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. National Academies Press. Accessed Jul 2026.
2. 2.Patel AK, Reddy V, Araujo JF (n.d.). Physiology, Sleep Stages. StatPearls Publishing. Accessed Jul 2026.
3. 3.Suni E, Sleep Foundation (updated 2025). Snoring: The Causes, Dangers, & Treatment Options. Sleep Foundation. Accessed Nov 5, 2026.
4. 4.Pacheco D, Sleep Foundation (updated 2025). The Best Temperature for Sleep. Sleep Foundation. Accessed Nov 5, 2026.