breathlessness vs exhalation

breathlessness

noun
  • The state of being breathless or out of breath. 

  • Difficult or labored respiration, dyspnea, shortness of breath 

exhalation

noun
  • The act or process of exhaling; breathing out 

  • A bright phenomenon; a meteor. 

  • That which is exhaled, or which rises in the form of vapor, fume, or steam 

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