Secondary Hypotheses: (1) Medical conditions that were reported as more frequent among Gulf War veterans compared to nondeployed veterans in the self-reported data in Phase I will be of equal prevalence in the two groups upon objective clinical examination. These include arthritis, dermatitis, hypertension, bronchitis, and asthma. (2) The prevalence of the above medical conditions in the primary hypotheses and secondary hypothesis (#1) will be equal between the spouses of Gulf War veterans and those of nondeployed veterans. (3) The prevalence of major birth defects found on a pediatric physical examination of veterans' biologic children conceived after the war to Gulf War veterans and nondeployed veterans will be equal; the prevalence of medical conditions in children living in the veterans' household, whether conceived before or after the war, for Gulf War veterans and nondeployed veteran will be equal.