paroxysm
n//pəˈɹɑk-//paroxysm
(countable, medicine) A period (especially one of several recurring periods) during the course of an illness when symptoms worsen; a sudden attack of a disease symptom, such as a bout of coughing or a seizure.
(countable) Chiefly followed by of: a sudden outburst of violent activity or feeling; also, the most severe part of an activity or incident; the climax.