Circadian rhythm
the 24-hour cycle of physical, mental, and behavioral changes that regulate the sleep-wake cycle and other bodily functions like hormone release and body temperature
Dreams
vivid mental experiences (images, stories, emotions) during sleep
Electroencephalograph (EEG)
a medical test that measures the electrical activity of the brain
Hypersomnia
a sleep disorder characterized by excessive daytime sleepiness and a prolonged need for sleep that leaves you feeling unrested
Insomnia
a common sleep disorder marked by difficulty falling asleep, staying asleep, or waking too early
Melatonin
a hormone your body naturally produces to regulate sleep
Napping
sleeping for a short period during the day to boost alertness, memory, and mood
Narcolepsy
appears to be a misspelling of narcolepsy, a chronic neurological disorder characterized by excessive daytime sleepiness, involuntary sleep episodes, and a sudden loss of muscle tone (cataplexy)
Night Terrors
episodes of screaming, thrashing, and panic that occur during deep sleep,
Nightmares
frightening, vivid dreams that occur during REM sleep, often causing fear, anxiety, or distress
Parasomnia
sleep disorders causing unusual behaviors, experiences, or movements during sleep, falling asleep, or waking
Restless Legs Syndrome
a neurological disorder characterized by an irresistible urge to move the legs, typically accompanied by uncomfortable sensations like crawling or aching
Sleep
a crucial biological process where the brain and body repair, restore, and process information, cycling through stages like REM and non-REM, essential for memory, immunity, hormone balance, and overall health
Sleep apnea
a sleep disorder characterized by repeated pauses in breathing during sleep, often accompanied by loud snoring
Sleep deprivation
when a person doesn't get enough sleep
Sleep paralysis
temporary inability to move or speak when falling asleep or waking up, often accompanied by a feeling of being awake but unable to move, and sometimes vivid hallucinations
Sleep study
a test to diagnose sleep disorders by monitoring brain waves, eye movement, muscle activity, and other vital signs during sleep
Snoring
a common sound from vibrations of throat tissues during sleep due to partial airway obstruction, often caused by relaxed muscles, sleeping on your back, alcohol, or nasal issues, with risk factors like age, obesity, and anatomy
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 final and most active stage of the sleep cycle
Somnambulism
a sleep disorder that involves walking or performing other complex behaviors while in a state of deep sleep, typically during the first third of the night
Wakefulness
the state of being awake, conscious, and aware of one's surroundings, as opposed to sleep