While much is yet to be proved conclusively as to the causes of Parkinson’s disease, both genetics and the environment ‒ and the interaction between the two ‒ are considered to play important roles in its origins. Those serving in the military are subject to several different occupational hazards known to be linked to Parkinson’s, from exposure to toxins and other environmental factors, to head injuries. Parkinson’s rates are higher among veterans than among the civilian population. Of the 1 million people in the US with Parkinson’s, an estimated 110,000 of them are veterans, who make up only 6% of the population.