Translation guide
Somnambulism, or sleepwalking, is a sleep disorder where a person walks or performs other complex behaviors while still asleep. This guide covers how to express this concept naturally in Japanese, from clinical terms to everyday descriptions.
To refer to the medical condition of sleepwalking in formal or technical contexts.
The formal medical term for somnambulism. Used in clinical settings, medical documents, and by healthcare professionals.
He was diagnosed with somnambulism.
A slightly older or less technical term for sleepwalking, still understood in medical contexts but less common than 睡眠時遊行症.
To describe sleepwalking in casual conversation or non-specialist writing.
To express the action of sleepwalking.
The most straightforward way to say 'to sleepwalk' as a verb phrase. It literally means 'to walk due to sleepwalking disease'.
To refer to a sleepwalker.
夢遊病 is the lay term for sleepwalking, while 睡眠時遊行症 is the formal medical diagnosis. In everyday conversation, 夢遊病 is perfectly acceptable and widely understood. Use 睡眠時遊行症 in clinical or academic writing.
Somnambulism is more common in children than adults.
Patients with somnambulism may walk around during sleep.
The most common lay term for sleepwalking. It literally means 'dream-walking disease' and is widely understood.
I used to sleepwalk as a child.
They say you shouldn't wake a sleepwalker.
A descriptive phrase meaning 'to walk while half-asleep/dazed'. It can refer to sleepwalking or just stumbling around groggily.
Last night I was sleepwalking and almost fell down the stairs.
A more explicit way to say 'to walk around due to sleepwalking'. It combines the noun with a verb phrase.
He was found wandering around while sleepwalking.
He often sleepwalks.
A casual verb phrase for sleepwalking, though it can also mean just walking while drowsy.
My child sleepwalked into the kitchen.
A rare, literary verb meaning 'to walk in one's sleep'. Not commonly used in modern conversation.
He has a habit of sleepwalking.
The standard term for a person who suffers from sleepwalking.
Sleepwalkers may engage in dangerous behavior.
A descriptive phrase meaning 'a person who walks while half-asleep'. More casual than 夢遊病者.
My younger brother is a sleepwalker, so I'm careful at night.
The doctor diagnosed him with somnambulism.
Childhood sleepwalking often resolves with age.
Somnambulism specifically involves walking or complex behaviors. Do not use 夢遊病 for nightmares (悪夢) or sleep talking (寝言).
I had a nightmare and screamed, but I wasn't walking around.
He was diagnosed with somnambulism after a sleep study.