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意識を失う

B1 verb #7,000 most common 8 min read

意識を失う

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Practice it Examples Notes & Tips 意識を失う in 30 Seconds

Explanation 意識を失う in your Level:

At the A1 level, you don't need to use 'ishiki o ushinau' often, but it's helpful to recognize. Think of it as the Japanese word for 'faint' in a serious way. You might learn 'neru' (sleep) first, but 'ishiki o ushinau' is different because it's not on purpose. It is made of 'Ishiki' (your mind being awake) and 'ushinau' (to lose). If you see someone fall down and they don't wake up, this is the word you would hear. It's a bit like saying 'They are gone' for a moment. Just remember that it's a very serious word, not for just taking a nap.

For A2 learners, you should start understanding how the verb 'ushinau' works. It is a transitive verb, meaning you 'lose' something. In this case, you lose your 'ishiki' (consciousness). You might use this when talking about a movie where a hero gets hurt. For example, 'Hero-wa ishiki-o ushinaimashita.' It's important to use the particle 'o' (を) between the two words. Also, notice the past tense 'ushinaimashita' or 'ushinatta.' This level is about being able to describe a simple event where someone passes out, perhaps during a hot day or an accident.

At the B1 level, you should be comfortable using 'ishiki o ushinau' in both formal and semi-formal contexts. You should understand the difference between this and 'ki o ushinau' (more common/casual) or 'kizetsu suru' (to faint/swoon). B1 learners should be able to use it in conditional sentences, like 'If you don't drink water, you might lose consciousness' (Mizu o nomanai to, ishiki o ushinau kamo shiremasen). This level requires knowing that 'ishiki' refers to the medical state of awareness. You might also encounter it in news reports about heatstroke or traffic accidents.

At B2, you should understand the more technical nuances of 'ishiki o ushinau.' It is often used in medical news or reporting where accuracy is paramount. You can use it to describe durations, like 'ishun ishiki o ushinau' (to lose consciousness for a second). You should also be able to recognize related noun phrases like 'ishiki soushitsu' (loss of consciousness). B2 learners should feel confident using this in a written report or a formal explanation of an event. You should also understand its use in sports commentary, such as when a fighter is knocked out.

C1 learners should appreciate the linguistic weight of 'ishiki o ushinau' in literature and high-level discourse. It can be used to describe profound psychological states or moments of existential transition. You should be able to distinguish it from 'shisshin' (syncope/fainting) and understand when 'ushinau' is used metaphorically in complex texts. At this level, you should also be aware of the passive form 'ishiki ga ushinawareru' in very specific literary contexts, though the active form remains standard. You can use it to discuss the philosophical nature of consciousness and what it means to 'lose' it.

At the C2 level, you possess a native-like grasp of 'ishiki o ushinau.' You understand its placement in medical legal documents, high-level philosophical debates about the mind-body problem, and its stylistic use in avant-garde literature. You can perfectly navigate the subtleties between 'ishiki o ushinau,' 'ki o ushinau,' and 'kizetsu suru' to convey exact tones of gravity, emotion, or clinical detachment. You are capable of using the phrase in complex grammatical structures, such as within nested relative clauses or as part of highly formal honorific speech when reporting to a superior about an incident.

Practice it Examples Notes & Tips

意識を失う in 30 Seconds

Formal phrase for losing consciousness or fainting.
Commonly used in medical, news, and dramatic contexts.
Combines 'ishiki' (consciousness) and 'ushinau' (to lose).
Indicates a serious physical state compared to casual terms.

The Japanese verb phrase 意識を失う (ishiki o ushinau) is the primary way to express the medical or physical state of 'losing consciousness' or 'fainting.' It is composed of two main parts: ishiki (意識), meaning consciousness, awareness, or senses, and ushinau (失う), a transitive verb meaning to lose something or to be deprived of something. Together, they create a formal and precise expression used in medical, journalistic, and literary contexts to describe someone passing out due to injury, illness, or shock.

Clinical Precision: In a hospital or emergency setting, this is the standard term used by doctors and paramedics. It describes the objective state of a patient who is unresponsive to stimuli. Unlike more colloquial terms, it doesn't imply a cause, just the state itself.
Dramatic Narratives: In novels, anime, and news reports, this phrase adds a layer of gravity. If a character 'ishiki o ushinau,' it suggests a serious condition, perhaps after a heavy blow in a battle or a sudden collapse from exhaustion. It is weightier than the English 'to black out.'

事故の衝撃で、彼はその場で意識を失った。
(Due to the impact of the accident, he lost consciousness on the spot.)

In everyday conversation, while people understand this phrase perfectly, they might opt for ki o ushinau (気を失う) or kizetsu suru (気絶する) for a slightly more natural or visceral feel. However, ishiki o ushinau remains the gold standard for clear, unambiguous communication. It is frequently seen in health warnings, such as those for heatstroke (nechuushou), where losing consciousness is a critical symptom requiring immediate intervention. Understanding this word is essential for anyone navigating Japanese healthcare or consuming serious media content.

熱中症の症状が進むと、意識を失うことがあります。
(As heatstroke symptoms progress, one may lose consciousness.)

Grammatical Composition: The verb 'ushinau' is a Godan verb. In the past tense, it becomes 'ushinatta' (lost). In the polite form, it is 'ushinaimasu.' Because it is a transitive verb, it requires the particle 'o' to connect to 'ishiki.'

Using 意識を失う correctly involves understanding its placement within various sentence structures, ranging from simple descriptive statements to complex conditional clauses. Since it describes a transition from one state (conscious) to another (unconscious), it is most frequently used in the past tense (ushinatta) or in potential/conditional forms when discussing risks.

1. Describing a Past Event: When recounting an incident, use the past tense. This is common in news reports or medical histories.

ボクサーは強烈なパンチを受けて、意識を失いました。
(The boxer took a powerful punch and lost consciousness.)

2. Warning and Conditions: When warning about health risks, the dictionary form or the '~tara' (if) form is used to show a consequence.

もし誰かが意識を失ったら、すぐに救急車を呼んでください。
(If someone loses consciousness, please call an ambulance immediately.)

In more formal or literary writing, you might see the noun form ishiki soushitsu (意識喪失), which means 'loss of consciousness.' However, ishiki o ushinau is more dynamic and common in spoken narrative. It can also be modified by adverbs to describe the speed or duration of the event, such as ishun (for a moment) or kanzen ni (completely).

彼女は痛みで一瞬意識を失ったようだ。
(It seems she lost consciousness for a moment due to the pain.)

3. Reporting Medical States: When doctors explain a condition to family members, they use this phrase to be precise without being overly jargon-heavy.

患者はまだ意識を失ったままです。
(The patient remains unconscious [in a state of having lost consciousness].)

You are most likely to encounter 意識を失う in environments where high stakes or medical emergencies are discussed. It is a staple of news broadcasting and dramatic fiction. Understanding the context helps in distinguishing it from lighter terms for 'feeling faint.'

News and Media: Television news reports regarding accidents, natural disasters, or heatwaves frequently use this phrase. When a reporter says 'ishiki fumei' (unconscious/consciousness unknown), they are using a related formal term, but 'ishiki o ushinaimashita' describes the event of losing it.
Medical Dramas & Anime: In Japanese dramas (J-Dramas) or anime, when a character collapses dramatically, onlookers or medical professionals will inevitably use this phrase. It signals to the audience that the character's condition is serious and not just a simple nap or a comedic fall.

アニメの主人公が強大な敵に敗れ、意識を失うシーンはよくあります。
(Scenes where the anime protagonist is defeated by a powerful enemy and loses consciousness are common.)

Public safety announcements (PSA) also heavily feature this phrase. During the humid Japanese summer, trains and stations often play announcements warning people to stay hydrated so they don't ishiki o ushinau. In these contexts, the phrase is a call to action, reminding the public of the physical dangers of the climate. Furthermore, in sports commentary—particularly combat sports like Judo, Karate, or Boxing—this phrase is used to describe a knockout.

猛暑の中での運動は、意識を失う危険があります。
(Exercising in extreme heat carries the danger of losing consciousness.)

Literature: Classic and modern Japanese literature use this phrase to describe internal shifts or the 'fading away' of a character's sense of self. It can sometimes be used metaphorically, though the physical meaning is predominant.

While 意識を失う is straightforward, learners often make mistakes regarding its formality, its similarity to other words, and particle usage. Avoiding these pitfalls will make your Japanese sound more natural and precise.

Mistake 1: Confusing with 'Naku-suru': Learners sometimes use 'naku-suru' (なくす) instead of 'ushinau' (失う). While both mean 'to lose,' ushinau is much more appropriate for losing something abstract or vital like consciousness, a life, or an opportunity. 'Naku-suru' is often used for physical objects like keys or wallets.
Mistake 2: Particle Errors: Using 'ga' (が) instead of 'o' (を) changes the meaning significantly. 'Ishiki ga ushinawareru' (passive) is possible but rare. 'Ishiki o ushinau' is the standard active form where the person is the subject.

❌ 意識が失った (Incorrect particle usage)
✅ 意識を失った (Correct: Lost consciousness)

Another common error is using this phrase when someone just falls asleep or is very tired. Ishiki o ushinau is exclusively for medical or emergency states. If someone falls asleep instantly, use bachi-to neru or kizuitara nete-ita. Using ishiki o ushinau for a nap might cause unnecessary alarm to Japanese listeners!

❌ 疲れすぎて意識を失った。
(Too heavy/dramatic for just falling asleep.)
✅ 疲れすぎて、いつの間にか寝てしまった。
(I was so tired, I fell asleep before I knew it.)

Mistake 3: Mispronouncing 'Ushinau': Ensure the 'u' sounds are distinct. It is u-shi-na-u. Some learners accidentally say 'ushinau' as 'ushiro' (behind), which creates total confusion.

There are several ways to say someone has passed out in Japanese, and choosing the right one depends on the formality of the situation and the perceived cause of the fainting.

気を失う (Ki o ushinau): This is the most common alternative. It uses 'ki' (spirit/energy) instead of 'ishiki.' It sounds slightly more natural in daily conversation and is used for emotional shocks or minor physical collapses.
気絶する (Kizetsu suru): A more sudden and dramatic term, often translated as 'to faint' or 'to swoon.' It is very common in literature and anime when a character sees something shocking or is hit hard.
倒れる (Taoreru): Literally 'to fall down' or 'to collapse.' This describes the physical action rather than the mental state. In many cases, it implies the person lost consciousness, but not always.

彼は驚きのあまり気絶した。
(He fainted from sheer surprise.)

For even more formal medical contexts, you might hear ishiki shougai (consciousness disorder) or konpaku (coma-like state). On the other hand, if someone is just feeling lightheaded but hasn't lost consciousness yet, you would use tachikurami (dizziness when standing) or memae (vertigo).

失神する (Shisshin suru): Another medical term for fainting. It is similar to 'kizetsu' but sounds a bit more like a clinical diagnosis. It is often used for brief losses of consciousness caused by low blood pressure.

貧血で失神する人が増えています。
(An increasing number of people are fainting due to anemia.)

How Formal Is It?

Fun Fact

In old Japanese, 'ushinau' was often used for losing one's way or losing a loved one, giving 'ishiki o ushinau' a very heavy, almost spiritual weight in classical literature.

Pronunciation Guide

UK i.ɕi.ki o u.ɕi.na.u

US i.ʃi.ki oʊ u.ʃi.nɑ.u

Pitch accent is generally flat (Heiban) for 'Ishiki' and 'Ushinau', but 'Ushinau' has a drop after 'na' in some dialects.

Rhymes With

Kizetsu Ushinau (rhymes with kau, au) Ishiki (rhymes with shiki, miki) Hiki Suki Toki Kaki Yaki

Common Errors

Pronouncing 'ushinau' as 'ushiro'.
Stressing the 'o' particle too much.
Merging 'i-shi' into a single 'she' sound.
Making the 'u' at the end too long.
Forgetting the 'i' at the end of 'ishiki'.

Difficulty Rating

Reading 3/5

Kanji for 'Ishiki' is common but requires study. 'Ushinau' is a basic verb.

Writing 4/5

Writing 'Ishiki' (意識) from memory can be tricky due to stroke count.

Speaking 2/5

Pronunciation is straightforward for English speakers.

Listening 2/5

Clear phonetic structure makes it easy to hear in news.

What to Learn Next

Prerequisites

意識失う倒れる体頭

Learn Next

意識不明気を失う気絶救急車診断

Advanced

脳震盪昏睡状態自己意識忘我

Grammar to Know

Transitive Verbs with 'o'

意識を失う (Lose consciousness)

Te-form for sequence

意識を失って、倒れた。

Hodo (Extent)

意識を失うほど痛い。

Sou da (Appearance)

意識を失いそうだ。

Mama (Remaining state)

意識を失ったままだ。

Examples by Level

彼は意識を失いました。

He lost consciousness.

Simple past polite form.

意識を失うのは怖いです。

Losing consciousness is scary.

Using 'no' to turn the phrase into a noun.

彼女はどこで意識を失いましたか？

Where did she lose consciousness?

Question form with 'doko' (where).

暑いと意識を失います。

If it's hot, you lose consciousness.

Conditional 'to' used for natural consequence.

意識を失わないでください！

Please don't lose consciousness!

Negative request form 'nai de kudasai'.

猫が意識を失った。

The cat lost consciousness.

Casual past tense.

おじいさんは意識を失いました。

The grandfather lost consciousness.

Polite past tense with a subject.

意識を失う、そして倒れる。

Lose consciousness, and then fall down.

Dictionary form used in a simple sequence.

昨日、友達が意識を失って病院に行きました。

Yesterday, my friend lost consciousness and went to the hospital.

Te-form used to connect two actions.

頭を打って、意識を失ったことがありますか？

Have you ever hit your head and lost consciousness?

Koto ga aru form for experience.

意識を失う前に、何が見えましたか？

What did you see before you lost consciousness?

Using 'mae ni' (before).

彼は急に意識を失いました。

He suddenly lost consciousness.

Adverb 'kyuu ni' (suddenly).

意識を失った人を見つけたら、助けてください。

If you find someone who has lost consciousness, please help them.

Relative clause 'ishiki o ushinatta hito'.

お酒を飲みすぎて意識を失うのは危ないです。

It is dangerous to lose consciousness from drinking too much alcohol.

Verb-sugiru (too much) + noun phrase.

彼女はショックで意識を失いそうになった。

She almost lost consciousness from the shock.

Sou ni naru (almost/seemed like).

意識を失うと、何も思い出せません。

When you lose consciousness, you can't remember anything.

Potential negative form of omoidasu.

事故の目撃者によると、運転手は衝突の直前に意識を失ったようです。

According to witnesses of the accident, the driver seems to have lost consciousness just before the collision.

Using 'ni yoru to' (according to) and 'you da' (seems like).

あまりの痛みに、彼は意識を失ってしまった。

Due to the intense pain, he ended up losing consciousness.

Te-shimau (regrettable completion).

山登り中に意識を失うのは、命に関わる問題です。

Losing consciousness while mountain climbing is a life-threatening issue.

Chuu (during) and inochi ni kakawaru (life-threatening).

彼女は一瞬意識を失ったが、すぐに気がついた。

She lost consciousness for a moment, but came to immediately.

Contrastive 'ga' (but) and 'ki ga tsuku' (to come to).

意識を失うほどの衝撃が体に加わった。

An impact strong enough to cause loss of consciousness hit the body.

Hodo (to the extent of).

もし意識を失ったら、このボタンを押すように言われていた。

I was told to press this button if I lost consciousness.

Passive form 'iwarete ita' and conditional 'tara'.

脱水症状で意識を失うケースが増えています。

Cases of losing consciousness due to dehydration are increasing.

Noun 'keesu' (case) and particle 'de' for cause.

薬の副作用で意識を失う可能性がある。

There is a possibility of losing consciousness due to side effects of the medicine.

Arumai (possibility) and 'de' for cause.

ボクシングの試合で、選手が強烈なフックを受けて意識を失った。

In a boxing match, a player took a powerful hook and lost consciousness.

Specific noun 'fukku' (hook) and 'ukete' (receiving).

彼は意識を失ったまま、集中治療室に運ばれた。

He was carried to the ICU while still unconscious.

Mama (remaining in a state) and passive 'hakobareta'.

意識を失うという体験は、彼に死の恐怖を教えた。

The experience of losing consciousness taught him the fear of death.

To iu (the act of) and 'oshieta' (taught).

高山病の最も深刻な症状の一つは、意識を失うことである。

One of the most serious symptoms of altitude sickness is losing consciousness.

Motto mo (most) and 'de aru' (formal copula).

貧血気味の彼女は、満員電車の中で意識を失いかけた。

She, being prone to anemia, almost lost consciousness in a crowded train.

Gimi (prone to/tendency) and 'kaketa' (on the verge of).

意識を失う原因を特定するために、精密検査が必要だ。

Detailed tests are necessary to identify the cause of the loss of consciousness.

Tame ni (in order to) and 'tokutei' (identify).

激しい運動の直後に意識を失うのは、心臓に問題があるかもしれない。

Losing consciousness immediately after intense exercise might indicate a heart problem.

Kamo shirenai (might).

意識を失うまでの記憶が全くない。

I have absolutely no memory up until the point I lost consciousness.

Made no (up until) and 'mattaku nai' (none at all).

その哲学者は、意識を失うことが自己の消失に繋がると論じた。

The philosopher argued that losing consciousness leads to the disappearance of the self.

Ronjita (argued) and 'tsunagaru' (leads to).

麻酔によって意識を失う際、奇妙な夢を見た。

When losing consciousness due to anesthesia, I had a strange dream.

Sai (formal 'when') and 'ni yotte' (by means of).

極度の緊張から意識を失うという現象は、医学的に説明可能である。

The phenomenon of losing consciousness from extreme tension is medically explainable.

Setsumei kanou (explainable).

意識を失う寸前に、彼は家族の名前を呼んだ。

Just before losing consciousness, he called out his family's names.

Sunzen (on the very brink).

脳への酸素供給が絶たれると、数秒で意識を失う。

If the oxygen supply to the brain is cut off, consciousness is lost in seconds.

Tatareru (cut off/passive) and 'suubyou de' (in a few seconds).

意識を失うという主観的な体験を言葉にするのは難しい。

It is difficult to put the subjective experience of losing consciousness into words.

Shukanteki na (subjective) and 'kotoba ni suru' (verbalize).

彼は意識を失うことを恐れるあまり、不眠症になった。

He became an insomniac because he feared losing consciousness so much.

Osoreru amari (so much that...).

意識を失うプロセスの解明は、現代医学の課題の一つだ。

Elucidating the process of losing consciousness is one of the challenges of modern medicine.

Kaimei (elucidation) and 'kadai' (challenge/task).

意識を失うという行為が、ある種の宗教的儀式においては超越への入り口とされる。

The act of losing consciousness is regarded as a gateway to transcendence in certain religious rituals.

Sareru (passive: is regarded) and 'chouetsu' (transcendence).

死の淵で意識を失う瞬間、生への執着が消え去った。

The moment I lost consciousness at death's door, my attachment to life vanished.

Shi no fuchi (death's door) and 'shuuchaku' (attachment).

意識を失うことの不可逆性が、その事故の悲劇性を際立たせている。

The irreversibility of the loss of consciousness highlights the tragic nature of the accident.

Fukagyakusei (irreversibility) and 'kiwadataseru' (highlight).

脳幹の損傷により、彼は永続的に意識を失う状態に陥った。

Due to brainstem damage, he fell into a state of permanent loss of consciousness.

Eizokuteki ni (permanently) and 'ochiitta' (fell into a bad state).

意識を失うというメタファーを通じて、作者は実存の脆さを描いている。

Through the metaphor of losing consciousness, the author depicts the fragility of existence.

Metafaa (metaphor) and 'jitsuzon' (existence).

自己意識を失うほどの忘我の境地に達した。

He reached a state of self-forgetfulness so intense he lost self-consciousness.

Bouga no kyouchi (state of ecstasy/self-forgetfulness).

意識を失う際のニューロンの活動パターンを詳細に分析する。

Analyze in detail the activity patterns of neurons when consciousness is lost.

Shousai ni (in detail).

意識を失う直前の脳波の乱れが、将来の発作を予見させる。

Disturbances in brain waves just before losing consciousness allow for the prediction of future seizures.

Yoken saseru (allows to predict/causative).

Common Collocations

一瞬意識を失う

完全に意識を失う

衝撃で意識を失う

痛みで意識を失う

病気で意識を失う

意識を失ったまま

意識を失いかける

突然意識を失う

意識を失う危険

意識を失う寸前

Common Phrases

意識を失うほど

— To the extent of losing consciousness. Used to describe intense pain or beauty.

意識を失うほど美しい景色。

意識を失った状態

— An unconscious state. Used in medical reports.

意識を失った状態が続いている。

意識を失う可能性がある

— There is a possibility of losing consciousness. Used in warnings.

この薬には意識を失う可能性がある。

意識を失うのを防ぐ

— To prevent losing consciousness. Used in health tips.

水分を摂って意識を失うのを防ぐ。

意識を失うまで

— Until one loses consciousness. Describes a duration of struggle.

意識を失うまで戦い続けた。

意識を失う原因

— The cause of losing consciousness. Diagnostic term.

意識を失う原因を調べる。

意識を失う瞬間

— The moment of losing consciousness.

意識を失う瞬間の記憶はない。

意識を失う頻度

— The frequency of losing consciousness. Medical questioning.

意識を失う頻度はどのくらいですか？

意識を失う兆候

— Signs of losing consciousness.

意識を失う兆候に気をつける。

意識を失う不安

— Anxiety about losing consciousness.

意識を失う不安を感じている。

Often Confused With

意識を失う vs 気を失う

More common in daily conversation, slightly less clinical.

意識を失う vs 気絶する

More dramatic/sudden, common in fiction.

意識を失う vs 寝る

Sleep is intentional; losing consciousness is not.

Idioms & Expressions

"我を忘れる"

— To lose oneself in excitement or anger. Not medical, but related to loss of self-control.

怒りで我を忘れてしまった。

Informal

"魂が抜ける"

— To look like one has lost their soul/consciousness (from shock).

驚きで魂が抜けたようになった。

Literary

"正気を失う"

— To lose one's sanity or senses.

彼はショックで正気を失った。

Formal

"前後不覚になる"

— To lose consciousness or become unaware of one's surroundings (often from drinking).

泥酔して前後不覚になった。

Neutral

"夢中になる"

— To be 'in a dream' (obsessed/focused), related to losing awareness of other things.

ゲームに夢中になる。

Informal

"茫然自失"

— To be stupefied/dazed (losing oneself from shock).

あまりの出来事に茫然自失とした。

Formal

"白河夜船"

— To be so fast asleep that one knows nothing of what's happening.

隣で何があっても白河夜船だ。

Idiomatic

"生きた心地がしない"

— To feel more dead than alive (from fear), near losing consciousness.

あの事故の時は生きた心地がしなかった。

Common

"幽体離脱"

— Out-of-body experience (sometimes used jokingly when fainting).

意識を失って幽体離脱した気分だ。

Slang

"ブラックアウト"

— To black out (loan word).

お酒でブラックアウトした。

Slang

Easily Confused

意識を失う vs 失う

Often confused with 'naku-suru'.

Ushinau is for abstract/vital things; Naku-suru is for physical objects.

財布をなくした (Lost wallet) vs 意識を失った (Lost consciousness).

意識を失う vs 意識

Sometimes confused with 'chui' (attention).

Ishiki is being awake; Chui is focusing.

意識がある (Is conscious) vs 注意する (Pay attention).

意識を失う vs 倒れる

They often happen together.

Taoreru is the physical fall; Ishiki o ushinau is the mental loss.

倒れたが、意識はある (Fell but is conscious).

意識を失う vs 失神

Both mean fainting.

Shisshin is a medical term for a brief faint; Ishiki o ushinau is broader.

彼は失神した (He fainted/syncope).

意識を失う vs 眠る

Both involve closed eyes.

Nemuru is natural sleep; Ishiki o ushinau is pathological/accidental.

ぐっすり眠る (Sleep soundly).

Sentence Patterns

[Person] wa ishiki o ushinaimashita.

田中さんは意識を失いました。

[Cause] de ishiki o ushinau.

暑さで意識を失う。

Ishiki o ushinatta toki, [Action].

意識を失った時、夢を見ました。

Ishiki o ushinau osore ga aru.

意識を失う恐れがある。

Ishiki o ushinau sunzen ni...

意識を失う寸前に声を上げた。

Ishiki o ushinau to iu joutai wa...

意識を失うという状態は不可解だ。

Ishiki o ushinai-sou ni naru.

意識を失いそうになった。

Ishiki o ushinatta koto ga aru.

意識を失ったことがあります。

Word Family

Nouns

意識 (Consciousness)

喪失 (Loss)

意識喪失 (Loss of consciousness)

Verbs

失う (To lose)

失われる (To be lost)

取り戻す (To regain)

Adjectives

意識的な (Conscious/Intentional)

無意識な (Unconscious/Automatic)

気絶

失神

昏睡

麻酔

覚醒

How to Use It

frequency

Common in news and medical contexts; moderate in daily speech.

Common Mistakes

意識がなくした → 意識を失った
Using 'nakushita' with 'ishiki' is grammatically awkward; 'ushinatta' is the set phrase.
意識が失った → 意識を失った
The particle 'ga' is wrong here; 'o' is needed for the direct object.
昨日、たくさん寝て意識を失った。 → 昨日、たくさん寝た。
Don't use this phrase for normal sleep.
意識を忘れる → 意識を失う
You don't 'forget' consciousness; you 'lose' it.
意識を負ける → 意識を失う
'Make-ru' means to lose a game; 'ushinau' is for losing a state.

Tips

Particle Choice

Always use 'o' (を) because you are the one losing the consciousness.

Related Noun

Learn 'Ishiki fumei' (意識不明) to understand news reports about accidents.

Heatstroke Awareness

In Japan, 'nechuushou' (heatstroke) is the #1 cause of 'ishiki o ushinau' in summer.

Don't Overuse

Don't use it for minor dizziness; use 'memae' or 'tachikurami' instead.

Kanji Breakdown

意 (mind) + 識 (know) = consciousness. Lose what you know in your mind.

Formal Reports

Use this phrase in business or medical reports for professional accuracy.

News Keywords

When you hear 'ishiki', pay attention; a serious story is coming.

Action Link

Link the word to the action of falling down to remember it better.

Clinical vs Narrative

Use 'ishiki o ushinau' for facts, 'ki o ushinau' for emotions.

Emergency Phrase

Memorize 'Ishiki ga arimasen!' (They are unconscious!) for emergencies.

Memorize It

Mnemonic

Think of 'Ishiki' as 'Is she key?' (Is consciousness the key?). And 'Ushinau' sounds like 'Pushing now' (She's pushing away her awareness). If she's pushing the key away, she loses consciousness.

Visual Association

Imagine a lightbulb (consciousness) being switched off or falling out of a person's head and shattering.

Word Web

Hospital Accident Faint Doctor Ambulance Brain Sleep Awake

Challenge

Try to use 'ishiki o ushinau' in a sentence describing a scene from your favorite action movie.

Word Origin

意識 (Ishiki) originated from Buddhist terminology (Vijnana), referring to the sense of discernment or the mind. 失う (Ushinau) is a native Japanese (Yamato Kotoba) verb meaning to lose or part with something.

Original meaning: The loss of one's discerning mind or spirit.

Sino-Japanese (Ishiki) + Native Japanese (Ushinau).

Cultural Context

Be careful using this word lightly; it implies a medical emergency. Don't use it to mean 'I fell asleep' or ' I was bored'.

English speakers use 'black out' or 'pass out' more casually than Japanese speakers use 'ishiki o ushinau'.

Ashita no Joe (Boxing anime) Medical dramas like 'Doctor X' News reports on the 2018 heatwave

Practice in Real Life

Real-World Contexts

Medical Emergency

意識はありますか？
意識を失っています。
すぐに救急車を！
原因は何ですか？

News Report

意識不明の重体
現場で意識を失い
病院に搬送された
命に別状はない

Sports

KO負け
意識を失う衝撃
試合中断
ドクターストップ

Weather/Heatstroke

水分補給
意識を失う危険
室内でも注意
無理をしない

Literature/Movies

意識が遠のく
暗闇に落ちる
目が覚めると
記憶が途切れる

Conversation Starters

"意識を失うような怖い経験をしたことがありますか？"

"熱中症で意識を失わないように、何をしていますか？"

"映画で主人公が意識を失うシーンについてどう思いますか？"

"もし道で誰かが意識を失っていたら、どうしますか？"

"意識を失うほど感動したことはありますか？"

Journal Prompts

今までで一番大きな怪我をした時のことを書いてください。意識を失いましたか？

日本の夏はとても暑いです。意識を失わないための対策をリストにしましょう。

『意識』とは何だと思いますか？意識を失っている間、人はどこにいるのでしょうか？

ドラマやアニメで、キャラクターが意識を失う演出について分析してください。

健康管理の大切さについて、意識を失うリスクを含めて書いてください。

Frequently Asked Questions

10 questions

No, it is only for medical emergencies or accidents. Using it for sleep is a mistake.

'Ishiki' is more formal and clinical; 'Ki' is more natural for daily stories.

Yes, but 'ki o ushinau' or 'ishiki ga tobu' (consciousness flew away) is more common for drinking.

Yes, especially in summer news reports about heatstroke.

You say 'ishiki o torimodosu' or 'ki ga tsuku'.

It is a standard verb. To make it polite, use 'ushinaimasu'.

It is understood but 'ushinau' is much more natural and common.

The kanji for 'ishiki' (意識) is JLPT N2 level, so it can be challenging for beginners.

If someone 'ishiki o ushinatta' and doesn't wake up quickly, you should call 119.

Yes, the phrase can be used for any living being with consciousness.