How to say "lung" in Japanese

• 肺はいJLPT N1approx.Common
  nounThe ordinary word for the organ itself, used in both everyday conversation and medical language. Whether you are talking about breathing, smoking, or a checkup, this is the word you want for 'lung'.
  喫煙きつえんが彼かれの肺はいを冒おかした。↗

  Smoking has affected his lungs.
• ルンゲCommon
  nounA loanword, from German 'Lunge'. For the organ this is seldom the word you want: 肺 is what Japanese uses in everyday speech and medical language alike, so you are unlikely to need it.
• ラングCommon
  nounA katakana rendering of 'lung'. Like ルンゲ, it is seldom the word you want for the organ; 肺 is the choice in every ordinary context, and ラング is rarely needed by learners.

For the organ itself, 肺 is the word Japanese uses in both everyday and medical contexts; 「ルンゲ」 and 「ラング」 are loanword equivalents you will rarely need, so default to 肺.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 肺はいlung
• ルンゲlung
• ラングlung