You use vicissitudes to refer to changes, especially unpleasant ones, that happen to someone or something at different times in their life or development.
例句
Whatever the vicissitudes of her past life, Jill now seems to have come through.不管過去經歷了什么坎坷，吉爾現在似乎都已經挺過來了。
英漢詞典釋義
n.
變遷,世事變化
A man used to vicissitudes is not easily dejected.飽經滄桑,不易沮喪。He experienced several great social vicissitudes in his life.他一生中經歷了幾次大的社會變遷。