decompensation

noun2

1. •
   The inability of a diseased or weakened organic system or organ to compensate for its deficiency, resulting in functional deterioration.

   • Once it was determined that hyperthyroidism was the probable etiology of her cardiac decompensation, the next step was treatment of the underlying disease. — 1982
2. •
   The deterioration of cognitive or emotional functionality in a person who is distressed or who suffers from a psychological disorder.

   • A varying percentage of our combat soldiers reach the limit of their endurance and must leave their foxholes, not for physical wounds but because of emotional decompensation. — 1945