insomnia

insomnia — noun

1. a persistent medical condition in which someone regularly cannot fall asleep, st

1.nounB2
Definition

a persistent medical condition in which someone regularly cannot fall asleep, stay asleep, or get enough deep rest night after night

Example

Rin's insomnia kept her awake until three in the morning.

possessive + insomnia as subject cause

Hassan tried drinking warm milk before bed to help with his insomnia.

collocation: help with insomnia

Common collocations
  • suffer from insomnia
  • chronic insomnia
  • struggle with insomnia
  • treat insomnia
  • insomnia symptoms
  • cause insomnia
  • acute insomnia
Synonyms
  • sleeplessness

    less medical, more general; used in everyday contexts like 'suffering from sleeplessness during exams'

  • wakefulness

    broader — can describe involuntary or voluntary staying awake; less specific about struggle to sleep

  • inability to sleep

    descriptive phrase rather than clinical term; useful for learners at lower CEFR levels

Antonyms
  • restful sleep

    the desired state that insomnia prevents

  • sound sleep

    uninterrupted, deep sleep — the opposite of the insomnia experience

Grammar Patterns

suffer from insomnia

have insomnia

struggle with insomnia

Usage Note

Uncountable — do not say 'an insomnia'. The condition is typically persistent rather than a single night of poor sleep. Often paired with 'chronic' (長期性的) for long-term cases or 'acute' (急性的) for short-term episodes triggered by stress or illness.

Common Mistakes

I have an insomnia.
I have insomnia.
'insomnia' is an uncountable noun and does not take 'a' or 'an'.
I couldn't sleep last night, so I have insomnia.
I've had trouble sleeping for weeks, so the doctor thinks it might be insomnia.
'insomnia' refers to a lasting condition, not a single restless night.

Word family

  • insomniac
    nounC1
  • insomniac
    adjectiveC1
  • sleepless
    adjectiveB2
  • sleeplessness
    nounB2

Synonym discussion

Sense: noun/1

All three describe a lack of sleep, but they differ in scope and formality. 'Insomnia' is the clinical term for a persistent condition — a doctor diagnoses insomnia, and it often requires treatment. 'Sleeplessness' is the everyday word: you can mention sleeplessness during exam week without implying a medical disorder. 'Wakefulness' is broader — it covers any state of being awake, whether voluntary or involuntary. For example: 'The baby's nighttime wakefulness exhausted the new parents' — here 'insomnia' would be wrong because the baby isn't trying to sleep. When choosing which word to use, consider whether the context is medical (insomnia), general (sleeplessness), or descriptive of being alert (wakefulness).

insomnia ↗sleeplessnesswakefulness

Common collocations

Nouns

Phrases

  • suffer from insomnia
  • struggle with insomnia
  • have trouble sleeping due to insomnia

Prepositions

  • with insomnia
  • from insomnia
  • for insomnia

Etymology

LatinEnglish

Borrowed from Latin 'insomnia' (sleeplessness), formed from 'in-' (not) + 'somnus' (sleep). The word entered English in the early 1700s as a medical term. The root 'somnus' also appears in 'somnolent' (sleepy) and 'somnambulism' (sleepwalking).