Gulf War Illness (GWI), which affects approximately 250,000 U.S. veterans, has been found to significantly reduce the ability of white blood cells to make energy and creates a measurable biochemical difference in veterans who have the disease. The finding comes from a physician who noticed GWI symptoms paralleled those of mitochondrial diseases. Analysis revealed significantly lower levels of extracellular acidification and oxygen consumption in the white blood cells of veterans with GWI.