Most adults need around 6-8 hours of sleep per night to function optimally.

Getting enough sleep can help with weight loss or maintenance, not weight gain.

The circadian rhythm is the body's natural sleep-wake cycle that regulates periods of sleepiness and wakefulness.

Awake is not a stage of sleep, but rather a state of consciousness.

REM sleep is associated with memory consolidation, emotional regulation, and learning.

Melatonin is a hormone produced by the pineal gland that helps regulate sleep-wake cycles.

Insomnia is a common sleep disorder characterized by difficulty falling asleep or staying asleep.

Loud snoring, gasping or choking during sleep, and excessive daytime sleepiness are all common symptoms of sleep apnea.

Narcolepsy is a neurological disorder characterized by sudden, irresistible urges to sleep.

Restless legs syndrome is characterized by uncomfortable sensations in the legs, an urge to move the legs, and worsening symptoms at night. Relief from symptoms with movement is not a common symptom.

Sleep paralysis is a temporary inability to move or speak when falling asleep or waking up.

Vivid, dream-like images, sounds or voices, and tactile sensations are all common symptoms of hypnagogic hallucinations.

REM sleep behavior disorder is a sleep disorder characterized by acting out dreams while asleep.

Caffeine consumption is a stimulant, not a relaxation technique.

Flow state, Zen state, and trance state are all terms used to describe a state of deep relaxation and focus.