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

At the time, Monroe was under the constant care of a doctor and a psychiatrist, who had prescribed her numerous medications to treat mental health issues as well as her insomnia. — Alex Gurley, PEOPLE, 4 Aug. 2026

How the trial has gone so far Last week, Patrick Clancy testified about his ex-wife’s downward spiral, full of hospital visits and about a dozen medications to treat her insomnia, anxiety and depression. — Eric Levenson, CNN Money, 3 Aug. 2026

The recurring power outages combined with the stifling heat have created collective insomnia on the island as residents struggle to get through the night. — ABC News, 3 Aug. 2026

Ultimately, glorifying sleep deprivation is counterproductive; prioritizing sleep is key for career longevity and productivity, while chronic insomnia leads to impaired judgment and hinders professional growth. — Mena Mirhom, Forbes.com, 1 Aug. 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