ARDS, or acute respiratory distress syndrome, is a life-threatening condition that affects the lungs. Most people who develop ARDS are already sick and in the hospital with another illness.
ARDS begins when the smallest blood vessels in the lungs lose their ability to hold fluid, allowing more fluid than normal to leave the blood vessels and leak into the alveoli, or air sacs. This can be caused by infection, trauma, injury, sepsis, aspiration, pneumonia or other conditions. As the alveoli fill with fluid, they cannot oxygenate the blood effectively.
As more and more fluid accumulates in the alveoli, the lungs are unable to provide enough oxygen to meet the needs of the body. If the condition becomes severe enough, and doesn't respond to treatment, the organs of the body can be starved of oxygen. This lack of oxygen can lead to death.
Sources:
What Is ARDS? National Heart Lung and Blood Institute. Accessed January 2011. http://www.nhlbi.nih.gov/health/dci/Diseases/Ards/Ards_WhatIs.html
