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 excessive daytime sleepiness, where individuals may feel tired and have a strong need to sleep even after getting adequate rest

Insomnia

a sleep disorder characterized by difficulty falling or staying asleep, leading to daytime fatigue and irritability.

Melatonin

a hormone that helps regulate the sleep-wake cycle, and it is also available as a supplement to help with sleep problems like insomnia and jet lag

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 uncomfortable sensations like crawling, tingling, or aching

Sleep

a vital biological process crucial for physical and mental health, during which the body performs essential functions like memory consolidation and toxin removal

Sleep apnea

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

Sleep deprivation

when you ar deprived of sleep

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

when doctors study your sleeping patterns

Snoring

the sound of obstructed breathing during sleep, caused by relaxed throat tissues vibrating as air passes through the airway

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

Stage 4 (REM Sleep)

the final and most active stage of the sleep cycle

Somnambulism

sleepwalking

Wakefulness

being awake