An exacerbation, in medicine, is the worsening of a disease or an increase in its symptoms. Examples includes an acute exacerbation of chronic obstructive pulmonary disease and acute exacerbation of congestive heart failure. An exacerbation, in medicine, is the worsening of a disease or an increase in its symptoms. Examples includes an acute exacerbation of chronic obstructive pulmonary disease and acute exacerbation of congestive heart failure.