sleep-wake cycle

American

[sleep-weyk] / ˈslipˈweɪk /

noun

Physiology. the species-specific biological pattern of alternating sleep and wakefulness, in humans roughly 8 hours of nocturnal sleep and 16 hours of daytime activity.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Melatonin is a hormone produced by the pineal gland that regulates the body's sleep-wake cycle.

From Science Daily • Nov. 4, 2025

Researchers believe magnesium may reduce cortisol, a stress hormone; increase melatonin, a hormone that promotes the sleep-wake cycle; and help regulate neurotransmitters for the central nervous system, per Medical News Today.

From Salon • Feb. 20, 2024

Lastly, melatonin is involved in biological rhythms, particularly circadian rhythms such as the sleep-wake cycle and eating habits.

From Textbooks • Jun. 9, 2022

"Carbohydrates can raise your blood sugar, which has a therapeutic sleeping effect. Tryptophan is the amino acid that leads to serotonin production. Serotonin can be converted into more melatonin, which promotes a healthy sleep-wake cycle."

From Fox News • Feb. 27, 2022

Sleep paralysis is commonly linked with narcolepsy, a rare condition that affects the brain’s ability to regulate the sleep-wake cycle.

From Washington Post • Jan. 26, 2018

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023