a) if someone or something is in trouble, they are in a situation with a lot of problems : He admitted that their marriage was in trouble.
get/run into trouble The company ran into trouble when it tried to expand too quickly.
in serious/deep trouble The economy was in serious trouble.
the dangers of trying to borrow your way out of trouble
b) if someone is in trouble, they have done something which someone will punish them for or be angry about in deep/big trouble We’ll be in big trouble if Mr Elliott finds out.
Reference : Longman dictionary