Gulf War syndrome is characterized by symptoms of fatigue, muscle pain, headaches, shortness of breath, memory loss, and diarrhea. This is a term used to describe symptoms of US military personnel who participated in the Persian Gulf War of 1990 - 1991 ("Operation Desert Storm"). Extensive study of these complaints produced several reports which concluded that the causes of these symptoms are multifactorial and may include exposure to chemical weapons and/or inhalation of toxins from burning petroleum products.