The VAs 2014 RAC report found Gulf War illness in "an excess of 26–32 percent of Gulf War veterans compared to nondeployed era veterans" in pre-2008 studies, and "an overall multisymptom illness prevalence of 37 percent in Gulf War veterans and an excess prevalence of 25 percent" in a later, larger VA study.According to a May 2018 report by the U.S. Department of Defense, "GWI is estimated to have affected 175,000 to 250,000 of the nearly 700,000 troops deployed to the 1990–1991 GW theater of operations. Twenty-seven of the 28 Coalition members participating in the GW conflict have reported GWI in their troops. Epidemiologic studies indicate that rates of GWI vary in different subgroups of GW Veterans. GWI affects Veterans who served in the U.S. Army and Marines Corps at higher rates than those who served in the Navy and Air Force, and U.S. enlisted personnel are affected more than officers. Studies also indicate that GWI rates differ according to where Veterans were located during deployment, with the highest rates among troops who served in forward areas." Research
Epidemiologic studies have looked at many suspected causal factors for Gulf War illness as seen in veteran populations. Below is a summary of epidemiologic studies of veterans displaying multisymptom illness and their exposure to suspect conditions from the 2008 U.S. Department of Veterans Affairs report.A fuller understanding of immune function in ill Gulf War veterans is needed, particularly in veteran subgroups with different clinical characteristics and exposure histories.
Gulf War syndrome or Gulf War illness is a chronic and multi-symptomatic disorder affecting military veterans of both sides of the 1990–1991 Persian Gulf War. 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 1991 Gulf War have enduring chronic multi-symptom illness, a condition with serious consequences.The Royal British Legion said research suggested up to 33,000 UK Gulf War veterans could be living with the syndrome, with 1,300 claiming a war pension for conditions connected to their service. In 2007 the Royal British Legion produced a comprehensive report entitled Legacy of Suspicion, which made recommendations about necessary research and compensation. The Royal British Legion is still campaigning for the UK government to properly address symptoms experienced by veterans of the Gulf War.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, chronic fatigue syndrome-like illness, post-traumatic stress disorder, and greater persistence of adverse health incidents.Exposure to pesticides and exposure to pills containing pyridostigmine bromide (used as a pretreatment to protect against nerve agent effects) has been found to be associated with the neurological effects seen in Gulf War syndrome.