表示患某种病，英语通常suffer from a disease。如：

He is suffering from viral meningitis. 他患病毒性脑膜炎。

More than three million people suffer from severe mental illness. 三百多万人遭受着严重心理疾病的折磨。

表示“遭受（痛苦等）”时，用 suffer sth和 suffer from sth，但稍有区别（并不绝对）：前者指直接遭受痛苦等，后者指“受……的影响而感到痛苦等”。比较：

England suffered a 2–0 defeat by Scotland. 英格兰队以0比2败给苏格兰队。

Two of the mountain climbers were suffering from frost-bite. 有两个登山者冻伤了。