Circadian rhythm

the body's internal 24-hour clock that regulates the sleep-wake cycle

Dreams

a subjective experience that most commonly occur during REM sleep, and can be caused by the brain processing daily information, re-experiencing memories, or other random signals

Electroencephalograph (EEG)

a medical test that measures the electrical activity of the brain

Hypersomnia

a condition characterized by persistent, excessive daytime sleepiness, even after adequate sleep

Insomnia

a common sleep disorder characterized by difficulty falling or staying asleep

Melatonin

a hormone your body naturally produces to regulate sleep

Napping

a short sleep during the day that can boost mood, alertness, and productivity

Narcolepsy

a chronic sleep disorder characterized by excessive daytime sleepiness and sudden "sleep attacks" that significantly impact daily life

Night Terrors

episodes of screaming, thrashing, and panic that occur during deep sleep, causing the person to seem terrified but remain unresponsive to being woken

Nightmares

disturbing dreams that can cause feelings of fear, anxiety, or sadness, and often cause the sleeper to wake up

Parasomnia

a sleep disorder characterized by abnormal behaviors, movements, or experiences that occur during sleep or while transitioning between sleep and wakefulness

Restless Legs Syndrome

a neurological disorder causing an irresistible urge to move your legs, often accompanied by unpleasant sensations like crawling, bubbling, or aching

Sleep

a vital biological process that allows the body and brain to rest and restore, cycling through different stages including non-REM and REM sleep

Sleep apnea

a disorder where breathing repeatedly stops and starts during sleep, causing poor sleep quality and potential health complications

Sleep deprivation

occurs when an individual fails to get the amount of sleep that they need

Sleep paralysis

temporary inability to move or speak while waking up or falling asleep, often accompanied by terrifying hallucinations or a feeling of pressure on the chest

Sleep study

a medical test that records brain waves, heart rate, oxygen levels, and other body functions while you sleep

Snoring

the sound produced by vibrating tissues in the upper airway during sleep, caused by a partial blockage that restricts airflow

Stage 1 (Non-REM) sleep

the initial, light stage of sleep that transitions you from wakefulness to sleep

Stage 2 (Non-REM) sleep

a light stage of sleep where the heart rate and breathing slow down, the body temperature drops, and eye movements stop

Stage 3 (Non-REM) sleep

the deepest stage of sleep, where the body repairs and regenerates tissues, builds bone and muscle, and strengthens the immune system

Stage 4 (REM Sleep)

the deepest stage of sleep, where the body repairs and regenerates tissues, builds bone and muscle, and strengthens the immune system

Somnambulism

sleepwalking

Wakefulness

the state of being awake, alert, and conscious of one's surroundings