Agony is unbearable suffering unto death which, unrelieved, must be borne regardless.

Agony is mentioned in various religions, as among Christians who point to the suffering of Christ along the via dolorosa and on the cross, and among Jews who point to the ethnic catastrophe of the Holocaust in Germany's Third Reich.

Agony has also a nosocomial provenance, e.g., the pain suffered in some terminal illnesses such as cancer, sometimes scarcely relieved even by heroin. In many U.S. hospitals, pain is measured on a self-anchoring scale from 0 to 9, in which the patient is asked to rank personal pain; 9 is considered agony.

Agony may also be inflicted, intentionally or not, by the State during the execution of prisoners, or deliberately during interrogation by torture.