For many years, plaintiffs in United States courts have sought to avoid established limits on tort claims, and to recover compensation even when traditional elements of a claim are absent. One variant of this effort has been the assertion of claims for medical monitoring, in which plaintiffs seek to recover medical expenses incurred in tracking health, despite the absence of a present injury. This theory is typically used to seek recovery of the future costs of medical testing needed to diagnose latent diseases that may be caused by exposure to a harmful substance, rather than compensation for an existing condition. Some US courts have allowed these claims to proceed, reasoning that the claim enables tort victims to detect and obtain treatment for latent disease at the earliest possible time. Other courts have refused to recognise the theory, adhering to the traditional principle that the lack of a current injury bars the claim.