Quick answer: To say “I’m sick” in Japanese, say 体調が悪いです (taichō ga warui desu) or 具合が悪いです (guai ga warui desu). For a cold, say 風邪です (kaze desu). Avoid 病気です (byōki desu) for everyday illness, because it sounds like a serious disease.
If you’ve learned basic Japanese, you might think:
“I’m sick” = 病気です
But here’s the truth…
This can sound unnatural (or even too serious) in everyday conversation.
I hear A LOT of people make this mistake because some textbooks teach you that…😭
So today, let’s break it down so you and your students can sound more natural 👇
🚫 What 病気です Really Means
病気（びょうき）です
is used when talking about:
- A serious illness
- A medical condition
- Something diagnosed by a doctor
Examples:
彼は病気です。
→ He is seriously ill.
病気で入院しています。
→ I’m hospitalized due to illness.
So if you say “病気(びょうき)です”, it might sound like: “I have a serious disease.”
Not what you mean when you just have a cold 😅
✅ Natural Ways to Say “I’m Sick”
Instead, use these 4 patterns depending on the situation to sound more natural :
- 体調が悪いです
- 具合が悪いです
- 風邪です
- ～が痛いです
① 体調が悪いです
→ “I’m not feeling well”
Safe, polite, and very natural
Works in any situation
Example:
体調が悪いので、今日は休みます。
→ I’m not feeling well, so I’ll take the day off.
② 具合が悪いです
→ “I feel sick / unwell”
Very common in daily conversation
Slightly more casual than 体調 (たいちょう)
Example:
ちょっと具合が悪いです。
→ I feel a bit sick.
③ 風邪です
→ “I have a cold”
Use when you know it’s a cold
Example:
風邪をひきました。
→ I caught a cold.
④ お腹が痛いです / 頭が痛いです
👉 Be specific!
お腹が痛い。
→ My stomach hurts.
頭が痛い。
→ I have a headache.
This is actually very natural in Japanese.
🎯 Simple Summary
| Japanese | Meaning | When to Use |
|---|---|---|
| 病気 (びょうき) です | Serious illness | Doctor-level / serious condition |
| 体調 (たいちょう) が悪 (わる)い | Not feeling well | Safe & polite |
| 具合 (ぐあい) が悪 (わる) い | Feel sick | Casual conversation |
| 風邪 (かぜ) です | Have a cold | Specific illness |
In English, people say “I’m sick” for everything.
But in Japanese, people:
👉 avoid vague expressions
👉 and often describe their condition more clearly
That’s why:
❌ 病気です → too heavy
✅ 体調が悪い → natural and flexible
🗣️ Quick Practice
Which one sounds natural?
- 病気ですから会社を休みます。
- 体調が悪いので会社を休みます。
Answer: #2 is natural!
✨ Final Takeaway
If you remember just one thing:
👉 Don’t use 病気です for everyday “I’m sick”
Instead, go with:
体調が悪い
具合が悪い
These will instantly make your Japanese sound more natural and native-like 🙌
Thank you so much for reading our blog posts! Please feel free to leave comments if you have any questions!
Keep learning: Visiting a Hospital in Japan? Useful Japanese Phrases You Need · Easily Say How You Feel: Hunger, Thirst, Tired · Daily Japanese Expressions with the Body
