Following traumatic injury some patients experience hypotension (low blood pressure) that is usually due to blood loss (hemorrhage) but can be due to other causes as well (for example, blood leaking around an abdominal aortic aneurysms). In the past, physicians were very aggressive with fluid resuscitation (giving fluids such as normal saline or lactated Ringer's through the vein) to try to bring the blood pressure to normal values. Recent studies have found that there is some benefit to allowing specific patients to experience some degree of hypotension in certain settings.