Translation guide
The state of being unconscious, not awake or aware. In Japanese, this is most commonly expressed with the noun 意識不明 (ishiki fumei) for medical or emergency contexts, or the verb phrase 気を失う (ki o ushinau) for 'to lose consciousness'. The choice depends on whether you are describing the state or the action of becoming unconscious.
Describing someone who is unconscious, often in a medical or accident context.
The standard term for 'unconscious' in news reports, medical settings, and emergencies. It literally means 'consciousness unknown/unclear'.
彼は意識不明の状態で病院に運ばれた。
He was taken to the hospital in an unconscious state.
A more conversational way to say 'unconscious', literally 'has no consciousness'. Used in everyday speech.
事故の後、彼は意識がなかった。
After the accident, he was unconscious.
Refers specifically to a coma or deep unconsciousness. More technical and severe than 意識不明.
患者は昏睡状態に陥った。
The patient fell into a coma.
Describing the act of becoming unconscious, such as fainting or blacking out.
The most common way to say 'lose consciousness' or 'faint'. Literally 'lose one's spirit/energy'.
彼女はその知らせを聞いて気を失った。
She lost consciousness when she heard the news.
A noun meaning 'fainting' or 'syncope'. Often used in medical contexts or formal descriptions.
A somewhat literary or dramatic term for fainting or collapsing. Not commonly used in everyday conversation.
Referring to the unconscious mind or lack of awareness in a psychological sense.
The standard term for the 'unconscious' in psychology (e.g., Freudian unconscious). Also means 'unaware' or 'unintentional' in daily use.
無意識のうちに彼の名前を呼んでいた。
I called his name unconsciously.
A literal phrase meaning 'state without consciousness', used when explaining the concept more broadly.
睡眠は意識のない状態に近い。
Sleep is close to a state of unconsciousness.
意識不明 (ishiki fumei) describes the ongoing state of being unconscious, often used in news or medical reports. 気を失う (ki o ushinau) is a verb phrase meaning 'to lose consciousness', focusing on the moment of fainting or passing out. Use 意識不明 for 'He is unconscious' and 気を失う for 'He lost consciousness'.
The English noun 'unconsciousness' does not have a single direct equivalent in Japanese that covers all contexts. Using 無意識 (muishiki) for medical unconsciousness would be incorrect; it primarily means 'unconscious' in the psychological sense or 'unaware'. Stick to 意識不明 or 気を失う for physical unconsciousness.
失神の原因を調べる必要がある。
We need to investigate the cause of the fainting.
暑さで卒倒しそうになった。
I almost fainted from the heat.