illness vs malaise

illness

noun
  • An instance of a disease or poor health. 

  • A state of bad health or disease. 

malaise

noun
  • A feeling of general bodily discomfort, fatigue or unpleasantness, often at the onset of illness. 

  • An ambiguous feeling of mental or moral depression. 

  • Ill will or hurtful feelings for others or someone. 

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