Glossary

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Sleep Science46Training Methods53Child Development23Sleep Environment38Schedules & Timing36Sleep Health40

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A

Adenosine

A chemical that builds up in the brain during waking hours and creates increasing pressure to sleep. It is cleared during sleep, especially deep sleep.

Awake Time

The total time a child spends awake during the day, including wake windows between naps and before bedtime. Tracking awake time helps dial in the right schedule.

Schedules & Timing

ABCs of Safe Sleep

A simple framework: Alone (no sharing a sleep surface), on their Back, in a Crib (or bassinet). These are the foundation of safe infant sleep.

Sleep Environment

Adenoids

Lymphoid tissue in the back of the nasal passage that can enlarge and obstruct breathing during sleep, contributing to snoring and sleep apnea in children.

Actigraphy

A method of monitoring rest and activity cycles using a wrist-worn device. Provides an estimate of sleep patterns over days or weeks in a home setting.

B

Bridging Nap

A short additional nap used to help a child make it to bedtime without becoming overtired. Often needed during nap transitions.

Schedules & Timing

Bedtime Routine

A consistent sequence of calming activities performed before sleep to signal the body and brain that sleep is coming. Typically includes activities like bathing, reading, and singing.

Training Methods

Bath Cue

Using a warm bath as part of the bedtime routine. The subsequent drop in body temperature after the bath can promote sleepiness.

Training Methods

Brown Noise

A deep, low-frequency sound similar to a strong wind or rushing waterfall. Some people find it more soothing than white or pink noise for sleep.

Sleep Environment

Blackout Curtain

Window coverings that block nearly all outside light. Important for creating a dark sleep environment, especially during summer months and for early morning waking.

Sleep Environment

Back to Sleep

The recommendation that babies should always be placed on their backs to sleep to reduce the risk of SIDS. Part of the Safe to Sleep campaign.

Sleep Environment

Bassinet

A small, portable sleep surface designed for newborns and young infants. Babies typically transition to a full-size crib when they outgrow the weight or size limit.

Sleep Environment

Bed Sharing

The practice of an adult and infant sharing the same sleep surface. Major pediatric organizations advise against bed sharing due to increased risk of SIDS and suffocation.

Sleep Environment

Bedtime Fading

A technique where bedtime is temporarily pushed later to align with when the child naturally falls asleep, then gradually moved earlier to the desired time.

Training Methods

Body Rocking

A rhythmic movement where a child rocks their body back and forth at bedtime or during the night. Often a self-soothing behavior that children outgrow.

Blue Light

Light in the blue wavelength spectrum emitted by screens and LED lights. It suppresses melatonin production and can delay sleep onset when exposure occurs close to bedtime.

Bedtime

The time at which a child is put down for nighttime sleep. An age-appropriate bedtime is one of the most impactful factors in sleep quality.

Schedules & Timing

Body Temperature

Core body temperature drops during sleep and is lowest in the early morning hours. This natural cooling supports sleep onset and maintenance.

Behavioral Insomnia of Childhood

A diagnosis that includes sleep onset association disorder and limit-setting type insomnia. It describes persistent difficulty falling or staying asleep related to behavioral factors.

Bedtime Resistance

When a child repeatedly stalls, protests, or refuses to go to bed at the designated bedtime. Common in toddlers and preschoolers testing boundaries.

Training Methods

Bedtime Pass

A behavioral tool where the child is given one pass per night that they can exchange for one acceptable request after bedtime. Helps reduce curtain calls.

Training Methods

Bruxism

Teeth grinding or clenching during sleep. Common in children and usually resolves on its own. Persistent cases may require a dental evaluation.

C

Circadian Rhythm

The internal 24-hour biological clock that regulates sleep-wake cycles, body temperature, and hormone release. Light exposure is the primary external cue that keeps this rhythm aligned with the day-night cycle.

Cortisol

A stress hormone that naturally peaks in the early morning to promote wakefulness. Elevated cortisol at bedtime can interfere with sleep onset.

Catnap

A short nap lasting 20 to 30 minutes. Common in young babies and sometimes used as a bridging nap later in the day to prevent overtiredness before bedtime.

Schedules & Timing

Consolidation

The process by which sleep becomes more organized over time, with longer stretches of nighttime sleep and fewer, longer naps during the day.

Cry It Out

A colloquial term often used for full extinction sleep training. The parent places the child down awake and does not intervene until a set time.

Training Methods

CIO

Abbreviation for cry it out. Refers to sleep training methods that involve allowing the child to cry without immediate parental intervention.

Training Methods

Chair Method

A gradual sleep training approach where the parent sits in a chair next to the crib and moves the chair farther away each night until they are out of the room.

Training Methods

Camping Out

A sleep training method where the parent stays in the child's room but gradually reduces their involvement and presence over time.

Training Methods

Comfort Object

An item such as a stuffed animal or small blanket that provides emotional security to a child. Typically introduced after 12 months for safety reasons.

Sleep Environment

Crib Safety

Standards and practices for a safe crib setup, including a firm mattress, fitted sheet, no bumpers, pillows, blankets, or stuffed animals.

Sleep Environment

Co-sleeping

A broad term that includes any sleeping arrangement where parent and child are in close proximity. It encompasses both bed sharing and room sharing.

Sleep Environment

Cosleeper

A bedside sleeper that attaches to the adult bed, allowing the baby to sleep on a separate surface within arm's reach. Provides proximity without bed sharing.

Sleep Environment

Crib to Bed Transition

The process of moving a child from a crib to a toddler or full-size bed. Most children make this transition between ages 2 and 3.

Child Development

CBT-I

Cognitive behavioral therapy for insomnia. A structured program that addresses thoughts and behaviors that prevent good sleep. The gold standard for adult insomnia.

Training Methods

Cognitive Behavioral Therapy for Insomnia

The full name for CBT-I. It combines cognitive restructuring with behavioral techniques like sleep restriction and stimulus control.

Training Methods

Confusional Arousal

A parasomnia involving partial awakening from deep sleep. The child may appear disoriented, cry, or thrash but is not fully conscious and typically returns to sleep.

Clock Based Schedule

A schedule where naps and bedtime occur at set times on the clock regardless of when the child last slept. Better suited for older babies and toddlers.

Schedules & Timing

Crib Hour

A practice where the baby is left in the crib for a full hour during nap time, even if they wake early, to give them the opportunity to fall back asleep.

Training Methods

Contact Nap

A nap where the child sleeps while being held by a caregiver. Common in the newborn stage and can become a sleep association.

Schedules & Timing

Car Nap

A nap that occurs in a car seat while driving. Like stroller naps, useful as a rescue option but the sleep quality is typically lower than crib sleep.

Schedules & Timing

Carrier Nap

A nap taken while the child is worn in a baby carrier. Combines contact and motion, making it effective for fussy babies but can create a strong sleep association.

Schedules & Timing

Circadian Low

A natural dip in alertness driven by the circadian rhythm, typically occurring in the early afternoon. This is an ideal time for napping.

Chronotype

An individual's natural preference for being a morning person or an evening person. Chronotype influences ideal bedtimes and wake times.

Curtain Calls

Repeated requests from a child after being put to bed, such as asking for water, another hug, or a bathroom trip. A form of bedtime resistance.

Training Methods

Colic

Excessive crying in an otherwise healthy infant, typically defined as crying for more than 3 hours a day, more than 3 days a week. Often disrupts family sleep patterns.

Child Development

Circadian Disruption

Any factor that misaligns the internal body clock with the external environment, such as travel across time zones, inconsistent schedules, or improper light exposure.

Cortisol Awakening Response

The natural spike in cortisol that occurs within 30 minutes of waking, promoting alertness and readiness for the day.

Cluster Feeding

A pattern of frequent, closely spaced feedings, often in the evening. Common in newborns and may help babies take in more calories before the longest sleep stretch.

Schedules & Timing

Caloric Intake

The total amount of calories consumed in a 24-hour period. Ensuring adequate daytime caloric intake supports the ability to sleep through the night.

Schedules & Timing

Check and Console

A sleep training variation where the parent enters the room at intervals to verbally or physically comfort the child without picking them up. Similar to timed checks.

Training Methods

Consistency

Applying the same approach every time in response to sleep behaviors. Consistency is the single most important factor in the success of any sleep training method.

Training Methods

Crib Bumper

Padded liners placed inside a crib. Major safety organizations recommend against their use due to suffocation, strangulation, and entrapment risks.

Sleep Environment

D

Deep Sleep

The most restorative stage of NREM sleep, also called slow wave sleep. Growth hormone is released during this stage, and it is hardest to wake someone from deep sleep.

Developmental Leap

A period of rapid brain development that can temporarily disrupt sleep, feeding, and mood. Babies often become fussier and clingier during leaps.

Child Development

Dream Feed

A feeding given to a sleeping or semi-sleeping baby, typically between 10 PM and midnight, with the goal of extending the longest stretch of nighttime sleep.

Schedules & Timing

Day Night Confusion

A common newborn issue where the baby sleeps longer stretches during the day and is more wakeful at night. Typically resolves by 6 to 8 weeks with light exposure cues.

Child Development

Desired Wake Time

The target time for a child to wake in the morning, used as an anchor point for building the rest of the day's schedule.

Schedules & Timing

Drowsy But Awake

Placing a baby in the crib when they are sleepy but still awake, so they can practice falling asleep independently. A foundational concept in many sleep training approaches.

Training Methods

Daylight Saving Time

The biannual clock change that shifts schedules forward or backward by one hour. Can disrupt children's sleep for several days. Gradual adjustment over a week is recommended.

Schedules & Timing

Dim Light Melatonin Onset

The point in the evening when melatonin levels begin to rise, signaling biological readiness for sleep. Abbreviated as DLMO.

Deep Pressure

Firm, evenly distributed pressure applied to the body that can have a calming effect on the nervous system. Used therapeutically in some sensory and sleep interventions.

Sleep Environment

Darkness

The level of light in the sleep environment. A very dark room supports melatonin production and reduces stimulation, promoting longer and deeper sleep.

Sleep Environment

E

Early Morning Waking

Waking for the day before 6:00 AM. Common causes include overtiredness, too much daytime sleep, a bedtime that is too late, or light leaking into the room.

Schedules & Timing

Epworth Sleepiness Scale

A questionnaire used to measure daytime sleepiness in adults. Scores above 10 suggest excessive daytime sleepiness that may warrant further evaluation.

Early Bedtime

Moving bedtime earlier than usual to compensate for a short nap day or missed nap. Helps prevent overtiredness and protects total sleep time.

Schedules & Timing

Enuresis

Involuntary urination during sleep, commonly called bedwetting. Normal in young children and typically resolves with age. May need evaluation if persistent past age 6 or 7.

EEG

Electroencephalogram. A test that measures electrical activity in the brain. Used in sleep studies to identify sleep stages and diagnose sleep disorders.

Extinction Burst

A temporary increase in the intensity or frequency of a behavior when reinforcement is removed. During sleep training, crying may get worse before it gets better.

Training Methods

F

False Start

When a baby wakes up 30 to 60 minutes after being put down for the night, often because they treated bedtime as a nap. Usually caused by an overtired or undertired state.

Schedules & Timing

Ferber Method

A graduated extinction sleep training approach developed by Dr. Richard Ferber. Parents check on the child at increasing intervals while the child learns to self-soothe.

Training Methods

Full Extinction

A sleep training method where the child is placed in the crib awake and the parent does not return until the next scheduled feed or morning. Sometimes called cry it out.

Training Methods

Fading

A gradual sleep training approach where the parent slowly reduces their level of intervention at bedtime over days or weeks.

Training Methods

Feed to Sleep

The practice of nursing or bottle-feeding a child until they fall asleep. Can become a negative sleep association if the child cannot return to sleep without feeding.

Training Methods

Four Nap Schedule

A daily sleep schedule with four naps, typical for young babies around 3 to 5 months of age when wake windows are still short.

Schedules & Timing

Ferritin

A blood protein that stores iron. Low ferritin levels have been linked to restless legs syndrome and poor sleep quality in children.

Full Feed

A complete feeding where the baby takes in a full serving of milk rather than snacking or comfort nursing. Full feeds during the day can reduce the need for night feeds.

Schedules & Timing

Fitted Sheet

A snug sheet designed to stay tightly on the mattress without bunching. It should be the only fabric on an infant's sleep surface.

Sleep Environment

G

Graduated Extinction

A sleep training method where parents leave the room and return at progressively longer intervals to briefly reassure the child. Also known as the Ferber method.

Training Methods

Gentle Sleep Training

An umbrella term for sleep coaching methods that involve minimal or no crying. Includes approaches like the chair method, pick up put down, and fading.

Training Methods

Growth Spurt

A period of accelerated physical growth that may temporarily increase hunger and disrupt sleep patterns. Typically lasts a few days.

Child Development

Growth Hormone

A hormone released primarily during deep sleep that supports physical growth and tissue repair. This is why deep sleep is especially important for growing children.

H

Homeostatic Sleep Drive

One of the two main processes governing sleep. It represents the body's increasing need for sleep based on how long a person has been awake.

Head Banging

A rhythmic movement where a child bangs their head against the mattress or crib during sleep onset. While alarming to parents, it is usually benign and self-limiting.

Hunger Cues

Signs that a baby is hungry, such as rooting, sucking on hands, or fussing. Distinguishing hunger cues from sleep cues helps determine the right response at night.

Child Development

Habitual Waking

A pattern of waking at the same time each night regardless of hunger or discomfort. Often maintained by learned behavior or schedule issues rather than a biological need.

High Need Baby

A term used for babies who are more intense, sensitive, and demanding. These children often require more support with sleep and may respond better to gradual approaches.

Child Development

Humidity

The moisture level in the air of the sleep environment. Maintaining 40 to 60 percent humidity can help prevent nasal congestion and promote comfortable breathing.

Sleep Environment

I

Independent Sleep

The ability to fall asleep without assistance from a caregiver, such as rocking, feeding, or holding. A key goal of many sleep coaching approaches.

Training Methods

Interval Method

Another name for graduated extinction or timed checks. The parent checks on the child at increasing time intervals during sleep training.

Training Methods

Iron Deficiency

A nutritional deficiency that can contribute to restless legs syndrome and disrupted sleep. Ferritin levels should be checked in children with persistent sleep movement issues.

Intermittent Reinforcement

Reinforcing a behavior only some of the time, which actually strengthens the behavior. In sleep training, inconsistency can make unwanted sleep behaviors more persistent.

Training Methods

J

Jet Lag

The temporary misalignment between the body's circadian rhythm and the local time zone after traveling. Adjusting light exposure and meal times helps reset the clock.

K

K-Complex

A large brain wave pattern seen during stage 2 NREM sleep, thought to help suppress arousal and keep the sleeper from waking.

L

Light Sleep

The initial stages of NREM sleep (stages 1 and 2) where the body transitions from wakefulness. A person in light sleep can be awakened easily.

Lovey

A small comfort object, often a stuffed animal or soft blanket, that a child becomes attached to and uses for self-soothing at sleep time.

Sleep Environment

Light Exposure

Exposure to natural or artificial light that influences circadian rhythm. Morning light helps set the clock, while evening light can delay sleep onset.

Last Nap to Bedtime Gap

The wake window between the end of the last nap of the day and bedtime. This is usually the longest wake window and is critical for preventing false starts.

Schedules & Timing

Limit Setting

Establishing clear and consistent boundaries around bedtime and sleep behaviors. Lack of limit setting is a common cause of bedtime resistance in toddlers and preschoolers.

Training Methods

Lip Tie

A condition where the tissue connecting the upper lip to the gum is unusually tight. Can affect latch during breastfeeding.

M

Melatonin

A hormone produced by the pineal gland in response to darkness. It signals the body that it is time to sleep and helps regulate the circadian rhythm.

Montessori Floor Bed

A mattress placed directly on the floor, often used in Montessori-style rooms. Allows the child freedom to get in and out of bed independently.

Sleep Environment

Moro Reflex

The startle reflex present in newborns, causing them to throw their arms outward when startled. It can wake a sleeping baby and is one reason swaddling is helpful.

Child Development

Motion Sleep

Sleep that occurs while in motion, such as in a stroller, car, or swing. Motion sleep is generally lighter and less restorative than stationary sleep.

Training Methods

Mouth Breathing

Breathing through the mouth rather than the nose during sleep. Chronic mouth breathing can affect facial development, sleep quality, and dental health.

Micro-Awakening

A very brief awakening lasting only seconds that occurs naturally between sleep cycles. Most people have no memory of these awakenings.

Magnesium

A mineral that plays a role in muscle relaxation and nervous system regulation. Some evidence suggests it may support sleep quality, though more research is needed.

Mesh Liner

A breathable liner for crib slats, sometimes used to prevent limbs from getting stuck. While safer than padded bumpers, many experts still advise against any liner.

Sleep Environment

N

NREM Sleep

Non-rapid eye movement sleep, which includes light sleep and deep sleep stages. It makes up the majority of total sleep time.

Night Waking

Any awakening that occurs between sleep onset and the final morning wake-up. Brief night wakings are normal between sleep cycles.

Nap

A daytime sleep period. The number and length of naps change as a child grows, with most children dropping to zero naps by age 3 to 5.

Schedules & Timing

Nap Transition

The process of dropping one nap from a child's daily schedule. Common transitions include 3-to-2 naps around 7 to 8 months and 2-to-1 around 13 to 18 months.

Schedules & Timing

Negative Sleep Association

A sleep association that requires caregiver involvement each time the child wakes, creating a cycle of dependency. Examples include feeding or rocking to sleep.

Training Methods

No-Cry Method

Sleep training approaches that aim to minimize or eliminate crying. These methods typically involve very gradual changes and more parental presence.

Training Methods

Nurse to Sleep

Breastfeeding a child to sleep. While natural and comforting, it can lead to a strong sleep association where the child needs nursing to fall back asleep during night wakings.

Training Methods

Night Feed

Any feeding that occurs during the nighttime sleep period. The number of night feeds typically decreases as a baby grows and can take in more calories during the day.

Schedules & Timing

Night Weaning

The process of gradually eliminating nighttime feedings. Most healthy babies can go through the night without feeds by 6 to 9 months, depending on weight and intake.

Schedules & Timing

Night Terrors

Episodes of screaming, intense fear, and flailing while still asleep, typically occurring during deep sleep. The child usually has no memory of the event.

Nightmares

Frightening dreams that occur during REM sleep and often wake the child. Unlike night terrors, the child is fully awake afterward and can describe the dream.

Newborn Sleep

Sleep patterns in the first few months of life, characterized by short sleep cycles, frequent waking, and no established circadian rhythm.

Child Development

Nap Strike

A period when a child who normally naps refuses to nap. Can be caused by developmental leaps, schedule issues, or readiness for a nap transition.

Schedules & Timing

Nasal Congestion

Blocked or stuffy nasal passages that can force mouth breathing and disrupt sleep. Common during colds, allergies, and teething.

Night Feeding Habit

A pattern where a child continues waking to feed at night out of habit rather than hunger. Common when the child has the caloric capacity to sleep through.

Schedules & Timing

Nightlight

A dim light source used in a child's room, typically for comfort or safety during nighttime bathroom trips. Red or amber light is preferred as it has less impact on melatonin.

Sleep Environment

O

Overtiredness

A state in which a child has been awake too long, causing a rise in cortisol and adrenaline that makes it harder to fall and stay asleep.

Object Permanence

The understanding that objects and people continue to exist even when out of sight. This cognitive milestone contributes to separation anxiety at bedtime.

Child Development

One Nap Schedule

A daily sleep schedule with a single midday nap, usually starting between 13 and 18 months. The nap typically falls around noon or early afternoon.

Schedules & Timing

OK to Wake Clock

A clock that changes color at a set time to signal when it is acceptable for the child to get out of bed. Helpful for early morning waking and limit setting.

Sleep Environment

Overtired Signs

Behavioral cues indicating a child has been awake too long, including hyperactivity, clumsiness, eye rubbing, and crankiness. Acting on these signs quickly prevents further overtiredness.

Child Development

Obstructive Sleep Apnea

A condition where the upper airway becomes partially or fully blocked during sleep, causing pauses in breathing. In children, enlarged tonsils and adenoids are a common cause.

Overdressing

Dressing a baby too warmly for sleep, which can increase the risk of overheating. Signs include sweating, damp hair, and flushed cheeks.

Overheating

A body temperature that is too high during sleep, potentially increasing the risk of SIDS. Maintaining proper room temperature and appropriate clothing helps prevent this.

P

Positive Sleep Association

A sleep association that a child can use independently, such as a pacifier they can replace themselves, a lovey, or white noise.

Training Methods

Pick Up Put Down

A sleep training technique where the parent picks up the crying child to calm them, then puts them back down once calm. Repeated as needed until the child falls asleep.

Training Methods

Pacifier

A silicone or rubber nipple given to a baby for non-nutritive sucking. Can be a positive sleep association once the child can replace it independently.

Sleep Environment

Pink Noise

A sound similar to white noise but with reduced higher frequencies, creating a deeper, more soothing tone. Examples include steady rain and heartbeat sounds.

Sleep Environment

Positive Bedtime Routine

A structured, enjoyable pre-sleep routine that creates positive associations with bedtime. Includes calming activities chosen by the child and parent together.

Training Methods

Pediatric Sleep Apnea

A condition where a child's breathing is partially or completely blocked repeatedly during sleep. Symptoms include snoring, mouth breathing, and restless sleep.

Parasomnias

A category of sleep disorders involving abnormal movements, behaviors, or experiences during sleep. Includes night terrors, sleepwalking, and confusional arousals.

Pineal Gland

A small endocrine gland in the brain that produces melatonin in response to darkness, helping regulate the sleep-wake cycle.

Polysomnography

The technical name for a sleep study. Sensors are placed on the body to record brain activity, eye movement, muscle tone, breathing, and oxygen levels during sleep.

Periodic Limb Movement

Repetitive, involuntary leg movements during sleep that can cause brief arousals. Related to but distinct from restless legs syndrome.

Protest Crying

Crying that expresses frustration or displeasure with a change, such as a new sleep routine. Distinct from distress crying, it tends to be intermittent rather than escalating.

Training Methods

R

REM Sleep

Rapid eye movement sleep, a stage characterized by vivid dreaming, rapid eye movements, and temporary muscle paralysis. It plays a key role in memory consolidation and emotional processing.

Rock to Sleep

Rocking a child in arms or a chair until they fall asleep. Can become a sleep association that the child depends on for every sleep onset.

Training Methods

Room Temperature

The ideal sleep environment temperature is between 68 and 72 degrees Fahrenheit. A room that is too warm or too cool can disrupt sleep.

Sleep Environment

Room Sharing

The practice of having the baby sleep in the same room as the parent but on a separate sleep surface. Recommended for at least the first 6 months.

Sleep Environment

Restless Legs

A condition characterized by an uncomfortable urge to move the legs, especially at rest and in the evening. Can delay sleep onset in children and adults.

Rhythmic Movement Disorder

Repetitive body movements such as head banging or body rocking that occur at sleep onset or during sleep. Common in infants and toddlers and usually resolves on its own.

Rescue Nap

A nap offered by any means necessary (stroller, car, carrier) when a regular nap fails and the child needs sleep to prevent overtiredness before bedtime.

Schedules & Timing

Rooting Reflex

A newborn reflex where the baby turns toward touch on their cheek and opens their mouth. While a hunger cue, it can also occur as a comfort-seeking behavior near sleep.

Child Development

Reflux

The backflow of stomach contents into the esophagus, common in babies. Can cause discomfort that disrupts sleep, especially when lying flat.

Regression

A temporary return to earlier behaviors or sleep patterns, often triggered by developmental milestones, illness, or environmental changes.

Child Development

Reverse Cycling

When a baby takes in more calories at night than during the day, often because daytime feedings are distracted or insufficient. Can perpetuate frequent night waking.

Schedules & Timing

S

Sleep Pressure

The growing biological need for sleep that accumulates the longer a person stays awake. Driven primarily by adenosine buildup in the brain.

Sleep Architecture

The overall structure and pattern of sleep stages throughout a night. A typical night cycles through light sleep, deep sleep, and REM sleep multiple times.

Sleep Cycle

A repeating pattern of sleep stages lasting roughly 90 minutes in adults and 45 to 60 minutes in infants. Each cycle includes light, deep, and REM sleep.

Slow Wave Sleep

Another name for deep sleep, named for the large, slow brain waves visible on an EEG during this stage. It is critical for physical restoration and immune function.

Sleep Onset

The transition from full wakefulness to sleep. The time it takes to fall asleep after lying down is called sleep onset latency.

Sleep Latency

The amount of time it takes to fall asleep after the lights go out. Typical healthy sleep latency is between 10 and 20 minutes.

Sleep Efficiency

The percentage of time spent actually sleeping compared to total time in bed. A sleep efficiency above 85% is generally considered healthy.

Split Night

When a child wakes in the middle of the night and stays awake for an extended period, often one to two hours. Commonly caused by too much daytime sleep or a bedtime that is too early.

Schedules & Timing

Sleep Need

The total amount of sleep a child requires in a 24-hour period. Sleep needs decrease gradually from infancy through childhood.

Self-Soothing

The ability of a child to calm themselves and return to sleep without external help. It is a learned skill that develops over time.

Training Methods

Sleep Association

Any condition or object a child connects with falling asleep. Associations can be positive (like a lovey) or negative (like needing to be rocked).

Training Methods

Sleep Crutch

A sleep association that requires caregiver involvement to maintain throughout the night, such as feeding, rocking, or holding. Also called a sleep prop.

Training Methods

Sleep Prop

Another term for sleep crutch. Any external aid a child depends on to fall asleep that must be provided by a caregiver each time they wake.

Training Methods

Shuffle Method

Another name for the chair method or sleep lady shuffle. The parent gradually moves their presence farther from the crib over several nights.

Training Methods

Swaddle

A technique of wrapping a baby snugly in a blanket to mimic the feeling of the womb. Swaddling should stop once a baby shows signs of rolling.

Sleep Environment

Sleep Sack

A wearable blanket that keeps a baby warm without loose bedding in the crib. Used as a safe alternative to blankets and as a replacement for swaddling.

Sleep Environment

Sound Machine

A device that produces consistent background noise to mask disruptive sounds during sleep. Should be placed at least three feet from the crib and kept at a safe volume.

Sleep Environment

Sleep Environment

The physical space where a child sleeps, including factors like darkness, temperature, noise level, and crib setup. A consistent sleep environment supports better sleep.

Sleep Environment

Safe Sleep

Guidelines established to reduce the risk of SIDS and sleep-related deaths. The core principles are a firm, flat surface with no loose items.

Sleep Environment

Sidecar Crib

A crib that attaches to the side of the adult bed with one side lowered or removed. Allows easy access for nighttime feeding while maintaining a separate sleep surface.

Sleep Environment

Sleep Regression

A period when a child who has been sleeping well suddenly has difficulty falling asleep, wakes more frequently, or resists naps. Common at 4, 8, 12, 18, and 24 months.

Child Development

Separation Anxiety

A normal developmental phase where a child becomes distressed when separated from their primary caregiver. Peaks around 8 to 10 months and again around 18 months.

Child Development

Scheduled Awakening

A technique where the parent wakes the child shortly before a habitual night waking to break the cycle. Over time, the scheduled wake-up is eliminated.

Training Methods

Sleep Restriction

A behavioral technique that limits time in bed to increase sleep drive and improve sleep efficiency. More commonly used in adult insomnia treatment.

Training Methods

Stimulus Control

A set of behavioral guidelines that strengthen the association between the bed and sleep, such as only using the bed for sleeping.

Training Methods

Sleep Hygiene

A set of habits and environmental factors that promote good sleep quality. Includes consistent schedules, a dark room, limited screen time, and regular exercise.

Sleep Diary

A daily log of sleep-related information including bedtime, wake time, night wakings, and nap times. Useful for identifying patterns and tracking progress.

Sleep Log

Another term for a sleep diary. A record of daily sleep patterns used by parents and sleep coaches to evaluate a child's sleep and make adjustments.

Sleepwalking

A parasomnia where a child walks or performs activities while still in deep sleep. Most common between ages 4 and 8. Safety measures are the primary intervention.

SIDS

Sudden infant death syndrome. The unexplained death of an apparently healthy baby, usually during sleep. Safe sleep practices significantly reduce the risk.

Startle Reflex

Another name for the Moro reflex. A normal newborn reflex that can disrupt sleep by causing sudden arm movements.

Child Development

Screen Time

Time spent viewing electronic screens. Screen use close to bedtime can interfere with sleep through blue light exposure, stimulating content, and delayed bedtime.

Sleep Training

The process of teaching a child to fall asleep independently. Encompasses a range of methods from gentle approaches to extinction-based techniques.

Training Methods

Sleep Coach

A professional who helps families improve their child's sleep through personalized plans and ongoing support. Also called a sleep consultant.

Training Methods

Sleep Consultant

A trained professional who assesses a child's sleep challenges and creates a customized plan. Credentials and training programs vary widely.

Training Methods

Sleep Plan

A structured, personalized strategy created to address a specific child's sleep challenges. Typically includes schedule adjustments, environmental changes, and a training method.

Training Methods

Schedule

The overall timing of sleep and wake periods throughout a 24-hour day, including nap times, wake windows, and bedtime.

Schedules & Timing

Stroller Nap

A nap taken in a stroller, often while moving. Can be used as a rescue nap but should not become the primary nap method if independent crib sleep is the goal.

Schedules & Timing

Sleep Debt

The cumulative effect of not getting enough sleep over time. Sleep debt can increase irritability, reduce learning capacity, and worsen overall sleep quality.

Sleep Inertia

The grogginess and reduced performance experienced immediately after waking, especially from deep sleep. It typically clears within 15 to 30 minutes.

Suprachiasmatic Nucleus

A tiny region in the hypothalamus that acts as the master circadian clock. It receives light signals from the eyes and coordinates the body's daily rhythms.

Sleep Spindle

A burst of brain wave activity during stage 2 NREM sleep. Sleep spindles play a role in memory consolidation and protecting sleep from external disturbances.

Sleep Onset Association Disorder

A condition where a child cannot fall asleep without specific conditions or objects, leading to difficulty with night wakings when those conditions are not present.

Sleep Terrace

A visual tool showing the progression of a bedtime routine as a series of descending steps, helping children understand and follow the sequence.

Training Methods

Sleep Window

The optimal time frame for putting a child to sleep, based on their sleep pressure and circadian rhythm. Missing the sleep window can lead to overtiredness.

Schedules & Timing

Sleep Cues

Behavioral signals that indicate a child is ready for sleep, such as yawning, rubbing eyes, pulling ears, or becoming fussy.

Child Development

Sleep Study

A medical test called polysomnography that monitors brain waves, breathing, heart rate, and movement during sleep. Used to diagnose sleep apnea and other disorders.

Snoring

Noisy breathing during sleep caused by vibration of tissues in the upper airway. Habitual snoring in children should be evaluated as it may indicate sleep apnea.

Sleep Fragmentation

Frequent brief awakenings during the night that reduce sleep quality even when total sleep time appears adequate.

Sleep Talking

Speaking or making vocal sounds during sleep without awareness. A common and generally harmless parasomnia, more frequent in children.

Sleep Onset Latency

The clinical term for the time it takes to transition from full wakefulness to sleep. Same as sleep latency.

Sleep Consolidation

The developmental process by which sleep periods merge into longer stretches. Nighttime sleep consolidates first, followed by daytime naps reducing in number.

Solid Food Introduction

The process of beginning complementary foods alongside breast milk or formula, typically around 6 months. Contrary to popular belief, starting solids does not automatically improve sleep.

Child Development

Sleep Onset Crying

Crying that occurs as a child transitions to sleep, particularly during sleep training. The duration typically decreases over several days as the child develops self-soothing skills.

Training Methods

Sleep Space

The designated area where a child sleeps, ideally used only for sleep to strengthen the association between the space and sleeping.

Sleep Environment

Sleep Surface

The mattress or pad on which a child sleeps. For infants, the surface must be firm and flat to meet safe sleep guidelines.

Sleep Environment

T

Total Sleep Time

The actual amount of time spent sleeping during a sleep period, not counting time awake in bed. It is a key metric in assessing sleep quality.

Timed Checks

A component of graduated extinction where the parent returns to the room at set intervals to briefly reassure the child without picking them up.

Training Methods

Transitional Object

A term from developmental psychology for an object that helps a child manage separation from a caregiver. A lovey or blanket commonly serves this role at bedtime.

Sleep Environment

Toddler Bed

A small, low bed designed for children transitioning from a crib. Often uses the same mattress as a crib and may have side rails.

Sleep Environment

Teething

The process of teeth erupting through the gums. While uncomfortable, research suggests teething causes less sleep disruption than commonly believed.

Child Development

Two Nap Schedule

A daily sleep schedule with two naps, typically a morning and an afternoon nap. Most common between approximately 7 and 15 months of age.

Schedules & Timing

Three Nap Schedule

A daily sleep schedule with three naps, common for babies between approximately 4 and 8 months of age.

Schedules & Timing

Tongue Thrust Reflex

A reflex in young babies that causes them to push solid food out of their mouth with their tongue. Unrelated to sleep but relevant when timing solid food introduction.

Child Development

Tonsils

Lymphoid tissue at the back of the throat. Enlarged tonsils are the most common cause of obstructive sleep apnea in children.

Tongue Tie

A condition where the tissue connecting the tongue to the floor of the mouth is unusually tight, potentially affecting breastfeeding and in some cases breathing during sleep.

Temperament

A child's innate behavioral style, including traits like adaptability, sensitivity, and intensity. Temperament influences how a child responds to sleep changes and training.

Child Development

TOG Rating

A measure of thermal resistance used to rate the warmth of sleep sacks and blankets. Higher TOG numbers indicate more warmth. Helps parents dress the child appropriately for room temperature.

Sleep Environment

U

Undertiredness

A state where a child has not built enough sleep pressure to fall asleep easily. Often caused by wake windows that are too short or too much daytime sleep.

Ultradian Rhythm

A biological rhythm with a cycle shorter than 24 hours. The 90-minute sleep cycle in adults is an ultradian rhythm.

V

Verbal Reassurance

Using a calm, consistent phrase to reassure a child during sleep training without physical contact. An example is saying a brief phrase like 'you are okay' from the doorway.

Training Methods

W

Wake After Sleep Onset

The total time spent awake after initially falling asleep and before final waking. Often abbreviated as WASO. High WASO can indicate fragmented sleep.

WASO

Abbreviation for wake after sleep onset. It measures cumulative time awake during the night after first falling asleep.

Wake Window

The period of time a child is awake between sleep periods. Appropriate wake windows vary by age and help prevent overtiredness or undertiredness.

Schedules & Timing

White Noise

A consistent sound that contains all frequencies at equal intensity. It helps mask environmental noises and can become a positive sleep association.

Sleep Environment

Wonder Week

A concept from the book The Wonder Weeks describing predictable developmental leaps in infancy. Each leap is associated with a fussy period followed by new skills.

Child Development

Wake Window Based Schedule

A schedule where naps are timed based on how long the child has been awake rather than clock time. Better suited for younger babies with variable wake times.

Schedules & Timing

Wake to Sleep

A technique where the parent gently stirs a sleeping child about 30 minutes before a habitual waking, disrupting the sleep cycle and potentially preventing the wake-up.

Training Methods

Witching Hour

A period of fussiness and crying that commonly occurs in the late afternoon and evening in young babies. Can make bedtime particularly challenging.

Child Development

Weighted Sleep Sack

A sleep sack with evenly distributed weight designed to provide gentle pressure. Safety and efficacy are debated, and some pediatric organizations advise caution.

Sleep Environment

Wearable Blanket

Another name for a sleep sack. A blanket with armholes that a child wears to stay warm without loose bedding.

Sleep Environment

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