Understanding Acute Respiratory Distress Syndrome (ARDS)

What is ARDS?

Acute respiratory distress syndrome (ARDS) is the sudden failure of the respiratory (breathing) system. It can develop in anyone over the age of 1 who is critically ill. A person with ARDS has rapid breathing, difficulty getting enough air into the lungs and low blood oxygen levels.

ARDS usually develops in people who are already very ill with another disease or who have major injuries. They are usually already in the hospital when they develop the ARDS.

Air you breathe in travels to the air sacs in your lungs. Small blood vessels run through the walls of the air sacs. Oxygen passes from the air sacs into the blood vessels and then into the bloodstream, which distributes the oxygen to all parts of the body. In ARDS, the lung's blood vessels leak more fluid than normal into the air sacs. This prevents the lungs from filling with air and moving enough oxygen into the bloodstream. The result is the body's organs don't get enough oxygen and they may shut down.

How Serious is ARDS?

Approximately 190,000 Americans are affected by ARDS annually.

ARDS can be life-threatening because your body's organs need oxygen-rich blood to function well. Up to 30% of ARDS cases can be fatal. That is a significant improvement from the 50%-70% death rate just 20 years ago.

Patients who develop ARDS due to trauma or a lung infection usually do better than those who develop the condition due to sepsis (infection of the blood).

If you have ARDS your lung function is likely to return to normal or near normal within several months. But some people with ARDS have lasting damage to their lungs or to areas outside the lungs.

What Causes ARDS?

Causes of ARDS include:

  • Sepsis (bacterial infection of the blood)
  • Trauma
  • Pneumonia or other lung infection
  • Multiple blood transfusions
  • Breathing in salt water
  • Breathing in harmful smoke or fumes
  • Breathing vomit into the lungs
  • Narcotics
  • Sedatives
  • Overdoses of tricyclic antidepressants
  • Shock

>> Learn more about the symptoms, diagnosis and treatment of ARDS.