insomnia

noun

in·​som·​nia in-ˈsäm-nē-ə 

: prolonged and usually abnormal inability to get enough sleep especially due to trouble falling asleep or staying asleep

chronic insomnia

Insomnia is a patient-reported problem characterized by difficulty falling asleep or difficulty maintaining sleep; ie, frequent awakenings, difficulty returning to sleep after awakenings, or awakening too early with inability to return to sleep.

—Daniel J. Buysse

Synonyms

• sleeplessness
• wakefulness

Examples of insomnia in a Sentence

has suffered from insomnia virtually his entire life

Recent Examples on the Web

Researchers from Iran, India, Italy and the UK were involved in the study, which first screened 1,740 couples for the presence or absence of insomnia. —Paul McClure 25, New Atlas, 25 May 2025

Eating a Mediterranean-style diet, which is higher in fats from fish and olive oil, was associated with a lower risk of insomnia and more time spent sleeping, according to a 2018 study by St-Onge and her coauthors. —Madeline Holcombe, CNN Money, 23 May 2025

Two months in, my stress, emotional suppression and insomnia caught up to me. —New York Times, 21 May 2025

Symptoms include tremors, insomnia, confusion, and diarrhea. —Tom Gavin, EverydayHealth.com, 12 May 2025

Word History

Etymology

Latin, from insomnis sleepless, from in- + somnus sleep — more at somnolent

First Known Use

1739, in the meaning defined above

Kids Definition

insomnia

noun

in·​som·​nia in-ˈsäm-nē-ə 

: prolonged inability to sleep

Medical Definition

insomnia

noun

in·​som·​nia in-ˈsäm-nē-ə 

: prolonged and usually abnormal inability to obtain adequate sleep especially due to difficulty falling asleep or staying asleep

called also agrypnia