Acute respiratory distress syndrome, or ARDS, is a very serious and often life-threatening lung condition that leads to low levels of oxygen in the blood. Without enough oxygen, many of your body's organs cannot function properly or may stop working altogether. A number of conditions can cause acute respiratory distress syndrome, but it usually occurs in people who are already sick with another disease or have a severe traumatic injury. Sometimes pneumonia can cause acute respiratory distress syndrome. Follow the links below to find WebMD's comprehensive coverage of acute respiratory distress syndrome, what it looks like, how to treat it, and much more.