Combat stress reaction or CSR, also known as shell shock or battle fatigue, is a short-term response to stress from combat. Symptoms can be emotional, physical, mental, and behavioral and may differ from person to person. Emotional symptoms include frustration, mood swings, anxiety, and sadness. Physical symptoms include body aches, trouble sleeping, panic attacks, and changes in appetite. Mental symptoms include difficulty focusing, obsessive thoughts, and impaired judgment. Behavioral symptoms include increased alcohol use, compulsive behavior, anger, isolation, and decreased sexual activity.