ARDS, or Acute Respiratory Distress Syndrome, is a medical condition that affects breathing and respiratory function. Damage to the lungs from preexisting conditions or serious infections like pneumonia causes fluid to flood the areas of the lungs that exchange used air for new air, and the affected person cannot take in a healthy amount of oxygen. Although this condition is very serious and can be lethal, treatment is available that is effective in some cases.
This is not a specific disease in itself; rather, it describes a certain type of breathing difficulty that can arise for a variety of reasons. The symptoms of Acute Respiratory Distress Syndrome point to an underlying cause. This can be a long term condition such as lung disease, traumatic lung injury, or infections. People who are 75 or older are at increased risk of ARDS, although it can occur at any time during a person's lifetime.
A normal lung contains little air sacs called alveoli, where incoming air swaps oxygen for the outgoing carbon dioxide from the body. Blood vessels form part of each alveoli, and act as transport highways for incoming oxygen and outgoing carbon dioxide. Liquid inside the vessels does not usually leak into the alveoli, and therefore the air sacs should have enough space to grab as much air as possible from a breath in, and transport as much carbon dioxide as possible outward in an exhalation. When the blood vessels or the lung tissue are damaged from an underlying lung condition, the fluid inside the vessels gets into the alveoli. This blocks up the alveoli and allows less air to come in and out of the body.
A patient suffering from Acute Respiratory Distress Syndrome has abnormally low levels of oxygen in his or her body. This makes some parts of the body, like the fingers or lips, turn blue from lack of oxygenation. The heart beats faster to try to move oxygen around and the person has to breathe rapidly to get in as much oxygen as possible. If enough oxygen does not get to the essential areas of the body, the organs, then these begin to lose function or cease function altogether, and the person can die.
Ventilation, which is the artificial delivery of oxygen into the lungs through a tube, can save a person with Acute Respiratory Distress Syndrome from dying. As ARDS is only a symptom of serious lung problems, however, the person may still be at risk of death, especially if complications like infections set in. The people who recover from ARDS may do so without any permanent loss of function, but others may suffer long term problems.