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 of insomnia

• restlessness
• wakefulness
• sleeplessness
• alertness

Examples of insomnia in a Sentence

has suffered from insomnia virtually his entire life

Recent Examples on the Web

Jurors heard testimony about her treatment by mental health professionals, psychiatric medications, anxiety, depression, insomnia and other symptoms documented before the killings. — Michael Ruiz , Adam Sabes , Greg Wehner, FOXNews.com, 4 Sep. 2026

Despite being prescribed over a dozen medications, Lindsay’s anxiety, depression and insomnia worsen. — Selena Barrientos, PEOPLE, 4 Sep. 2026

How Sleep Patterns Connect to Hemorrhoid Risk A study published in Neuropsychiatric Research in August 2026 examined whether sleep patterns like insomnia, sleep duration and daytime napping may influence the risk of developing hemorrhoids. — Samantha Agate, Miami Herald, 3 Sep. 2026

New research is bringing sound sleep health into the gut-adjacent conversation, using genetic methodology to probe whether insomnia, sleep duration and daytime napping causally influence hemorrhoid risk. — Samantha Agate, Fort Worth Star-Telegram, 3 Sep. 2026

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