Shell shock (also called bullet wind, soldier’s heart, battle fatigue, and operational exhaustion) is a phrase coined in World War I to described the type of PTSD many soldiers were afflicted with during the war (before PTSD itself was a term). It is reaction to the intensity of the bombardment and fighting that produced a helplessness appearing variously as panic and being scared, or flight, an inability to reason, sleep, walk or talk.
During the War, the concept of shell shock was ill-defined. Cases of ‘shell shock’ could be interpreted as either a physical or psychological injury, or simply as a lack of moral fibre. While the term shell shock is no longer used in either medical or military discourse, it has entered into popular imagination and memory, and is often identified as the signature injury of the War.
In World War II and thereafter, diagnosis of ‘shell shock’ was replaced by that of combat stress reaction, a similar but not identical response to the trauma of warfare and bombardment.