exacerbation
noun /ɪɡˌzæsəˈbeɪʃn/
  /ɪɡˌzæsərˈbeɪʃn/
 [uncountable, countable] (formal)- the act of making something worse, especially a disease or problem- the exacerbation of religious and racial tensions
- Over the next two years, Gary experienced numerous acute exacerbations of his illness.