Translation guide
The English word 'hair' refers to the strands growing on the human head, body hair, or a single strand. Japanese distinguishes these carefully, and using the wrong word can sound unnatural.
Referring to the hair on one's head as a whole.
The standard word for the hair on your head. Use this for general statements about hairstyle, color, length, etc.
Literally 'hair of the head'. Slightly more concrete than 髪, often used when talking about individual strands or the physical hair itself.
髪の毛が抜けた。
My hair fell out.
Loanword from English, used mainly in compound words like ヘアスタイル (hairstyle) or ヘアケア (hair care). Not used alone for 'hair'.
新しいヘアスタイルにした。
I got a new hairstyle.
Referring to one individual hair.
Can mean a single strand when used with counters like 一本 (いっぽん).
スープに髪の毛が入っていた。
There was a hair in my soup.
Generic word for hair/fur. For a single strand, it's often used in compounds or with counters, but 髪の毛 is more common for head hair.
毛が一本落ちている。
There's a single hair on the floor.
Referring to hair on arms, legs, chest, face, etc.
Referring to hair on the face.
General term for facial hair, including beard, mustache, and stubble. Use this for any facial hair.
ひげを剃る。
I shave my beard.
彼はひげを生やしている。
He has a beard.
Specifically a mustache.
Specifically a beard (chin hair).
Referring to the coat of an animal.
The English loanword ヘア is not used by itself to mean 'hair'. It only appears in compounds like ヘアスタイル or ヘアカラー. Saying ヘアが長い is unnatural; use 髪が長い.
髪 (かみ) is specifically head hair. 毛 (け) is body hair, animal fur, or a generic term. 髪の毛 (かみのけ) is head hair but often emphasizes the physical strands. For 'I have long hair', 髪が長い is best. For 'There's a hair in my food', 髪の毛が入っている is natural.
体毛の処理方法について調べる。
I'm researching body hair removal methods.
I trim my mustache.
I'm growing a beard.