Translation guide
Japanese has several words for menstruation, ranging from clinical to euphemistic. The most common everyday term is 生理 (seiri), which literally means 'physiology' but is the standard word for 'period'. More direct terms like 月経 (gekkei) are used in medical contexts. There are also many slang and euphemistic expressions.
生理中です。
I'm on my period.
生理が遅れています。
My period is late.
The speaker wants to refer to menstruation in a neutral, everyday context, such as talking with friends, family, or in casual conversation.
The most common and natural word for 'menstruation' or 'period'. It literally means 'physiology', but in context it is understood as menstruation. Used by all genders and ages in everyday speech.
生理が始まった。
My period started.
生理中はお腹が痛い。
I have stomach pain during my period.
生理が遅れている。
My period is late.
The formal, medical term for menstruation. Used in clinical settings, health classes, or official documents. Not typically used in casual conversation.
月経周期は約28日です。
The menstrual cycle is about 28 days.
月経痛がひどいです。
I have severe menstrual cramps.
Abbreviation of 'menstruation', used as slang, especially among younger women. Can sound a bit dated or girlish.
今メンスなんだよね。
I'm on my period right now.
The speaker wants to refer to menstruation indirectly, often to be polite, discreet, or humorous.
Literally 'that day', a common euphemism for the day one's period starts or the period itself. Used in casual conversation among women.
あの日が近いからイライラする。
I'm irritable because my period is coming soon.
Literally 'girl's day', a euphemism used to refer to menstruation, often in a lighthearted or discreet way.
今日は女の子の日でちょっとだるい。
It's that time of the month and I feel a bit sluggish.
The speaker wants to talk about specific aspects of menstruation, such as cramps, PMS, or sanitary products.
Menstrual cramps or period pain. A common compound using 生理 (period) + 痛 (pain).
生理痛がひどくて薬を飲んだ。
My cramps were so bad I took medicine.
Irregular menstruation. Used in both casual and medical contexts.
生理不順で悩んでいます。
I'm worried about my irregular periods.
Premenstrual syndrome. Often used as-is in Japanese, sometimes written as 月経前症候群 (げっけいぜんしょうこうぐん) in medical contexts.
PMSの症状がつらい。
My PMS symptoms are tough.
Sanitary napkin/pad. The most common term for pads.
Tampon. Loanword from English.
生理 (seiri) is the everyday word used in conversation, while 月経 (gekkei) is the formal medical term. Using 月経 in casual talk can sound stiff or overly clinical. Stick to 生理 for most situations.
生理はいつも何日ぐらい？
How many days does your period usually last?
月経周期を記録してください。
Please record your menstrual cycle.
Direct translations like 月経期間 (gekkei kikan) for 'menstrual period' are not natural in everyday Japanese. Use 生理期間 (seiri kikan) or simply 生理中 (seiri-chuu) instead.
Literally 'monthly thing', a traditional euphemism. Can sound old-fashioned or poetic.
月のものが来た。
My monthly visitor has arrived.
Sanitary products (pads, tampons, etc.). A general term.
生理用品を買いに行く。
I'm going to buy sanitary products.
I change my pad.
I'm scared to use tampons.