cause vs complication

cause

noun
  • The source of, or reason for, an event or action; that which produces or effects a result. 

  • Sufficient reason for a state, as of emotion. 

  • A goal, aim or principle, especially one which transcends purely selfish ends. 

  • A suit or action in court; any legal process by which a party endeavors to obtain his claim, or what he regards as his right; case; ground of action. 

verb
  • To actively produce as a result, by means of force or authority. 

  • To set off an event or action. 

complication

noun
  • The act or process of complicating. 

  • A person who doesn't fit in with the main scheme of things; an interloper. 

  • The state of being complicated; intricate or confused relation of parts; complexity. 

  • A feature beyond basic time display in a timepiece. 

  • A disease or diseases, or adventitious circumstances or conditions, coexistent with and modifying a primary disease, but not necessarily connected with it. 

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