difficulty vs trouble

difficulty

noun
  • An awkward situation or quarrel. 

  • Physical danger from the environment, especially with risk of drowning 

  • An obstacle that hinders achievement of a goal. 

  • The state of being difficult, or hard to do. 

  • An objection. 

  • That which cannot be easily understood or believed. 

trouble

noun
  • A distressing or dangerous situation. 

  • A difficulty, problem, condition, or action contributing to such a situation. 

  • A fault or interruption in a stratum. 

  • A malfunction. 

  • A violent occurrence or event. 

  • Efforts taken or expended, typically beyond the normal required. 

  • Liability to punishment; conflict with authority. 

  • Wife. Clipping of trouble and strife. 

verb
  • In weaker sense: to bother or inconvenience. 

  • To mentally distress; to cause (someone) to be anxious or perplexed. 

  • To worry; to be anxious. 

  • To take pains to do something. 

How often have the words difficulty and trouble occurred in a corpus of books? (source: Google Ngram Viewer )