The United States has provided benefits in varying degrees to those who have worn the uniform and suffered disabilities in service to the nation. In general, a veteran is entitled to compensation for disabilities incurred in or aggravated during active military, naval, or air service. It should be noted that not all persons who served in the military are considered veterans for purposes of veterans benefits. Veterans could meet the burden of proving that their disabilities are service-connected through their military records, which may clearly describe and document the circumstances and medical treatment for an injury or an illness incurred while in service as well as any resulting disability. However, where the manifestation of the disability is remote from the veteran's service and any relationship between the disability and service is not readily apparent, the burden of proving service connection can be a challenge. In such circumstances, Congress and the Department of Veterans Affairs (VA) have relied on presumptions.