Gulf War syndrome (GWS) or Gulf War illness (GWI) affects veterans and civilians who were near conflicts during or downwind of a chemical weapons depot demolition, after the 1991 Gulf War. A wide range of acute and chronic symptoms have included fatigue, loss of muscle control, headaches, dizziness and loss of balance, memory problems, muscle and joint pain, indigestion, skin problems, immune system problems, and birth defects. Approximately 250,000 of the 697,000 veterans who served in the 1991 Gulf War are afflicted with enduring chronic multi-symptom illness, a condition with serious consequences.

Exposure to toxic chemicals is currently believed to be the cause of the illness. Several specific causes have been investigated, including pyridostigmine bromide (PB) nerve gas antidote (NAPP) pills, organophosphate military strength pesticides, chemical weapons, and depleted uranium. Causes which have been ruled out include post traumatic stress disorder, anthrax vaccinations, and smoke from oil well fires, though these exposures may have led to various illnesses and symptoms in a limited number of Gulf War veterans. PB or NAPP antidote pills given to protect troops from nerve agents and military strength insecticides used during deployment have currently been most closely linked to Gulf War veterans' chronic multi-symptom illness. Exposure to the destruction of the Khamisiyah weapons depot, where large quantities of Iraqi chemical munitions containing sarin and cyclosarin nerve agents was stored, is negatively correlated with motor speed. Epidemiological evidence is consistent with increased risk of birth defects in the offspring of persons exposed to depleted uranium.

Twenty years on from the first Gulf War, charities say more than 9,000 British veterans are still suffering from a cocktail of war-related health problems.

The National Gulf Veterans and Families Association claim more needs to be done to support former soldiers who are suffering from chronic headaches, cognitive difficulties, depression, unexplained fatigue, rashes and breathing problems.
Maria Rusling from the association told Sky News: "Although some veterans are on war pensions and benefits, a lot of them are still fighting not only the benefit system but the illnesses they have."

Thousands of troops from Britain and other countries fell ill with what is sometimes called Gulf War Syndrome, after the conflict began two decades ago.