Understanding Sleep: A Deep Dive into Sleep Cycles, Disorders, and Their Impact on Health
Sleep is an essential part of life—one that plays a critical role in health and well-being for both children and adults. Yet, sleep disorders are widespread, affecting up to 70 million people in the U.S. alone. Understanding how sleep works, what happens during each stage, and the conditions that can disrupt sleep is vital for both parents and healthcare practitioners.
This article will break down the normal sleep cycle, explore common sleep disorders, and discuss how sleep quality impacts overall health in both pediatric and adult populations.
The Basics: Understanding the Sleep Cycle
Sleep is divided into two major categories:
Non-rapid Eye Movement (NREM) Sleep – A deeper, restorative sleep phase.
Rapid Eye Movement (REM) Sleep – The dream state, crucial for brain function and emotional regulation.
Each night, our body SHOULD cycle through these stages 4-5 times, with each cycle lasting about 90 minutes.
Stages of NREM Sleep
NREM sleep is further divided into three distinct stages:
💤 Stage 1 (Light Sleep)
This is the transition stage between wakefulness and sleep.
Brain activity slows down, and alpha and theta waves appear.
Sleep in this stage is easily disrupted—even slight noises can wake a person up.
Common issue: Increases with age, leading to more nighttime awakenings.
💤 Stage 2 (Deeper Light Sleep)
Brain waves slow further, and sleep spindles and K-complexes occur.
Sleep spindles play a role in memory consolidation and neuroplasticity (important for learning in kids).
Sleep spindle activity is reduced in Alzheimer’s disease (AD) and autism spectrum disorder (ASD), potentially serving as an early diagnostic marker.
💤 Stage 3 (Slow-Wave Sleep – SWS)
This is the deepest and most restorative sleep stage.
It’s associated with:
✅ Growth hormone release (critical for childhood development)
✅ Cellular repair and immune function
✅ Memory processingSWS decreases with age and is lower in women than in men.
Common issues: Night terrors and sleepwalking occur in this stage, particularly in children.
REM Sleep: The Dream Stage
Characterized by rapid eye movement, low-amplitude brain waves, and muscle paralysis (atonia).
Essential for memory consolidation, learning, and emotional regulation.
Comprises 20-25% of total sleep in adults but decreases with age.
Common sleep disorder: REM Behavior Disorder (RBD), where people physically act out their dreams.
Common Sleep Disorders and Their Impact on Health
1️⃣ REM Sleep Disorders
REM Behavior Disorder (RBD)
People with RBD physically act out their dreams, sometimes violently.
Often linked to neurodegenerative diseases such as Parkinson’s disease (PD) and dementia.
Research suggests that RBD may be an early warning sign of Parkinson’s, with up to 37% of patients later developing neurodegenerative conditions.
Common Treatment options:
🔹 Melatonin – Shown to reduce symptoms by resynchronizing circadian rhythms.
🔹 Clonazepam – Historically used, but associated with drowsiness and increased fall risk in older adults.
2️⃣ Sleep-Disordered Breathing (Sleep Apnea)
Obstructive sleep apnea (OSA) occurs when airflow is blocked during sleep, leading to snoring, gasping, and daytime fatigue.
It is most common in middle-aged, overweight men but can also affect children (due to enlarged tonsils/adenoids).
Associated with:
✅ Increased risk of heart disease, diabetes, and cognitive decline
✅ Higher likelihood of sleep apnea during REM sleep due to muscle paralysis
Diagnosis: Overnight polysomnography (sleep study) or home sleep apnea test.
3️⃣ Insomnia
Most common sleep disorder in both adults and children.
Can be categorized as:
🔹 Sleep-onset insomnia (trouble falling asleep)
🔹 Sleep-maintenance insomnia (waking up frequently at night)
Women are more likely to suffer from insomnia, especially after stressful life events.
4️⃣ Restless Leg Syndrome (RLS) & Periodic Limb Movements of Sleep (PLMS)
RLS is a strong urge to move the legs, often described as a “creepy-crawly” sensation.
PLMS is involuntary leg jerking that can disrupt sleep.
Caused by:
✅ Iron deficiency
✅ Dopamine dysregulation (common in Parkinson’s disease)
✅ Chronic conditions like diabetes or kidney disease
5️⃣ Narcolepsy
A neurological sleep disorder causing excessive daytime sleepiness (EDS).
Type 1 narcolepsy includes cataplexy, a sudden loss of muscle tone triggered by strong emotions.
Diagnosis requires a sleep study and multiple sleep latency test (MSLT).
How Sleep Changes With Age
As we age, sleep architecture shifts:
📉 Less slow-wave sleep (SWS) → Reduced deep sleep means less recovery and repair.
📈 More stage 1 sleep → Lighter sleep leads to more frequent awakenings.
⏳ Increased sleep fragmentation → More nighttime disruptions linked to cognitive decline.
Studies show poor sleep increases the risk of Alzheimer’s disease due to the buildup of beta-amyloid plaques in the brain. Sleep fragmentation is also linked to higher dementia risk.
Improving Sleep for Kids and Adults
🌿 Lifestyle & Natural Interventions
The key to treatment is addressing the right area of your sleep cycle suspected to be altered to find the relief you need.
Here are some general ways to get sleep back on track:
Regulate circadian rhythms → Keep a consistent sleep schedule.
Reduce blue light exposure → Avoid screens 1-2 hours before bed.
Ensure proper sleep environment → Keep the room dark, cool, and quiet.
Exercise → Regular movement improves sleep quality and sleep-spindle activity.
When to Seek Medical Help
Loud snoring, gasping, or excessive daytime sleepiness → Could indicate sleep apnea. (A home sleep study is a great option)
Kicking or jerking legs during sleep → Consider RLS or PLMS.
Acting out dreams → Could be a sign of REM Behavior Disorder (RBD).
Severe insomnia impacting daily function → Needs further evaluation.
Final Thoughts
Sleep is not just a passive process—it’s an active, vital part of health and development. Understanding the different sleep stages and recognizing disorders early can help prevent long-term complications in both children and adults.
If you or your child are struggling with sleep issues, addressing the root cause is essential rather than relying on sleep aids.
As a naturopathic doctor, I take a holistic approach to sleep health, considering everything from circadian rhythms to nutrient deficiencies and nervous system imbalances.
Here to empower you with the knowledge of health,
Dr. Meg Holpuch
Disclaimer: The information provided on this blog is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. The content shared here is not meant to replace or supersede the guidance or recommendations of your personal healthcare provider. Always consult your physician or qualified healthcare professional before making any changes to your diet, exercise routine, supplement regimen, or overall health plan. Your health and well-being are unique, and decisions regarding your care should always be made in consultation with your trusted healthcare provider.
