An infection of the lungs (often bacterial or viral) causing inflammation; commonly presents with cough, fever, and breathing difficulty (pneumonia).
祖父は高熱が続き、検査の結果、肺炎と診断された。
My grandfather had persistent high fever and was diagnosed with pneumonia after tests.
新型ウイルスによる肺炎の患者が増えている。
The number of pneumonia cases caused by the new virus is increasing.
軽い風邪でも高齢者は肺炎に進行しやすいので注意が必要だ。
Even a mild cold can progress to pneumonia in elderly people, so caution is needed.