Battle fatigue

Battle fatigue is an obsolete term which may refer to:
 * Combat stress reaction, a military term for an acute reaction to the stress of battle commonly involving fatigue, slowed reaction time, indecision, and other symptoms
 * Posttraumatic stress disorder, a medical term for a chronic disorder associated with psychological trauma
 * Shell shock, a term used in WWI for an uncontrolled strong nervous reaction to the battle's horrible and extreme unhuman conditions