The patient later developed a serious problem, one that could not have been detected earlier.

病人后来出现了一种严重的疾病，一种不能较早发现的疾病。

youdao

After this period, some patient developed long-term fatigue.

在此之后，一些病人出现长期疲劳。

youdao

Two years later, the patient developed chest pain;

两年后患者发生胸痛；

youdao

Two years later, the patient developed chest pain;

两年后患者发生胸痛；

youdao