A collection of varying symptoms, such as persistent tiredness, headaches, muscle pain and poor concentration, reported by members of the Coalition Armed Forces who served in the 1991 Gulf War. Whilst there is strong evidence for a health effect related to service, there is no evidence of a specific set of signs and symptoms (the definition of a ‘syndrome’) unique to those who served in the Gulf War. Symptoms have been blamed by sufferers on exposure to depleted uranium munitions, smoke from oil-well fires and use of pesticides. However, the only clearly demonstrated association is with the particular pattern of vaccinations used to protect against biological weapons. Many conflicts in the past have generated their own ‘syndromes’, given names such as effort syndrome and shell-shock, suggesting a link to the psychological stress of being in the midst of warfare.