患难

trials and tribulations

to suffer (from illness) / to contract (a disease) / misfortune / trouble / danger / worry

difficult (to...) / problem / difficulty / difficult / not good

disaster / distress / to scold

a friend in times of tribulations (idiom); a friend in need is a friend indeed

true sentiments are seen in hard times (idiom) / you see who your true friends are when you go through tough times together / you see who your true friends are when you are in difficulties

to go through thick and thin together (idiom)