Gulf War syndrome. Gulf War syndrome (GWS) also known as Gulf War Illness or Chronic Multi-symptom Illness, is a chronic and multi-symptomatic disorder affecting military veterans of both sides of the Gulf War (1990???1991). A wide range of acute and chronic symptoms have been linked to it, including fatigue, muscle pain, cognitive problems, insomnia, rashes and diarrhea. Approximately 250,000 of the 697,000 U.S. veterans who served in the Gulf War have enduring chronic multi-symptom illness, a condition with serious consequences. From 1995 to 2005, the health of combat veterans worsened in comparison with nondeployed veterans, with the onset of more new chronic diseases, functional impairment, repeated clinic visits and hospitalizations, myalgic encephalomyelitis/chronic fatigue syndrome-like illness, post-traumatic stress disorder, and greater persistence of adverse health incidents. Gulf War illness is linked to exposure to sub-lethal amounts...