If the bacterial load suddenly increases, it causes symptoms like cough and fever, a decrease in lung function, and sometimes changes on a chest X-ray, and this is called a CF exacerbation and usually prompts a round of antibiotics.

如果细菌数量突然增加，就会有类似咳嗽、发烧、肺功能减退的症状，有时候可以在X线胸片上看到改变，这就是CF急变，这时经常需要使用一轮抗生素。