suffer sth与suffer from sth的基本区别：

▲suffer sth中的suffer为及物动词，牛津词典对此的解释是：experience or undergo (sth unpleasant) 经历或遭受（不愉快之事），此用法中的suffer通常后接pain, grief, loss, punishment, hardship等表示“痛苦”或“损失”的名词作宾语。如：

Her failure to act in time caused the company to suffer a big loss. 她没及时采取行动，使公司蒙受了巨大的损失。

The doctors were worried that he might have suffered brain damage. 医生们担心他可能受到了脑损伤。

He suffered a severe injury and his prospects for living are grim. 他严重受伤，活下来的可能性很不乐观。

▲suffer from sth中的suffer为不及物动词，牛津词典对此的解释是：feel pain, discomfort, great sorrow, etc 感到疼痛、不适、悲伤等；受苦；吃苦头。其中的介词from表示原因，指“因……而受到受苦等”。如：

She suffers from arthritis. 她患有关节炎。

Many people suffer from insomnia. 许多人都患有失眠症。

The population of that country suffers from hunger. 那个国家的人民忍饥挨饿。

If you suffer from depression, it’s best to get professional help. 如果你患有抑郁症，最后向专业人士求助。