突然发病的英文：
sudden onset

sudden是什么意思：
adj. 突然的，意外的；快速的
n. 突然发生的事

A sudden loud blow or bump.
砰然作响发出砰一声的猛击或猛撞

A sudden, striking surprise;a twist.
意外发展突然的、惊人的变化；意想不到的转折

Hasty climbers have sudden falls
大起者有大落

go into a sudden nosedive
突然俯冲.

Meleager felt a sudden pang.
墨勒阿格突然觉得一阵疼痛。

onset是什么意思：
n. 开始，着手；攻击；发病

No one can stop the onset of winter.
没有一个人能够阻止冬天的“进攻”。

The fierce onset of the enemy broke the ranks of the army.
敌人的猛烈攻击致使全军大乱。

Most of the passes have been closed with the onset of winter.
冬天来临，大部分关口均已关闭。

Her life was finally extinguished by the onset of liver complaint.
她的生命之火终因肝病发作而被掐灭了。

The onset of the Great Depression undercut much of the credibility of the quantity theory.
大萧条的出现大大削弱了货币数量论的信誉。