REM Breathing Patterns: What Happens to Your Lungs While You Dream?

July 28, 2025

Sleep is a time of restoration and mystery, with rapid eye movement (REM) sleep holding a special place as the stage where most dreaming occurs. But what happens to your breathing during REM sleep—and why does it matter for your lung health and overall wellness? In this article, we explore the science behind REM breathing patterns, their connection to brain activity, and implications for conditions like sleep apnea and respiratory disorders.

What Is REM Sleep?

REM sleep is one of the five stages of the sleep cycle, characterized by:

Rapid movement of the eyes under the eyelids
Brain activity resembling wakefulness
Muscle atonia (near-paralysis of voluntary muscles)
Vivid dreaming

REM typically occurs about 90 minutes after falling asleep and repeats every 90-120 minutes throughout the night.

How Does Breathing Change in REM?

Unlike the steady, rhythmic breathing seen in non-REM sleep, REM breathing is irregular and variable. Key features include:

Variable rate and depth: Breaths may speed up or slow down unpredictably.
Reduced ventilatory drive: The brain’s automatic control of breathing diminishes, making breathing more dependent on behavioral inputs.
Brief pauses: Short episodes of hypoventilation or central apnea (temporary cessation of breathing) can occur.
Increased upper airway resistance: Muscle atonia causes relaxation of throat muscles, which can lead to partial airway collapse in susceptible individuals.

This variability reflects the complex brain activity during REM and the disconnect between respiratory control centers and muscle movement.

Why Does REM Breathing Matter?

REM sleep is vital for memory consolidation, emotional regulation, and physical restoration. However, the irregular breathing pattern in REM can exacerbate existing respiratory problems and unmask issues like:

Obstructive Sleep Apnea (OSA): Airway collapse is often worse during REM due to muscle relaxation.
Central Sleep Apnea: Irregular breathing control can cause pauses.
Nocturnal Hypoxemia: Fluctuations in breathing may reduce oxygen levels intermittently.

Studies show that REM-related breathing disruptions are strongly linked to cardiovascular risk, daytime sleepiness, and cognitive decline.

How Is REM Breathing Studied?

Sleep labs use polysomnography (PSG) to monitor:

Respiratory rate and effort
Blood oxygen saturation (SpO2)
Airflow via nasal/oral sensors
Muscle activity (EMG) to detect atonia

Advanced techniques like capnography (measuring CO2 levels) and brain imaging have enhanced understanding of breathing control during REM.

Can We Improve REM Breathing?

Managing REM breathing irregularities involves:

Treating underlying sleep apnea with CPAP or oral appliances
Lifestyle changes such as weight loss, avoiding alcohol/sedatives before bed
Positional therapy to prevent airway collapse
Monitoring with wearable devices that track oxygen and breathing patterns overnight

Emerging therapies, including neurostimulation to enhance airway muscle tone during REM, are under investigation.

Takeaway: Breathing While You Dream

Your lungs don’t take a break when you sleep—especially during REM, when breathing patterns become a delicate dance influenced by brain activity. Understanding REM breathing helps clinicians better diagnose sleep-related breathing disorders and tailor treatments to improve both sleep quality and lung health.