Acute Respiratory Distress Syndrome (ARDS)

What is ARDS?

Acute respiratory distress syndrome, or ARDS, is a very serious lung problem that may happen when a person is critically ill. With ARDS, fluid fills the air sacs of both lungs.  This causes the lungs to become swollen (inflamed). ARDS makes it hard to breathe.  Acute lung injury (ALI) is similar to ARDS but not as serious as ARDS. ALI and ARDS can happen after:

  • Pneumonia
  • Traumatic injuries, such as car accidents and severe burns
  • An infection carried throughout the body known as “sepsis”
  • Shock
  • Some complicated surgeries

Cigarette smoking, alcohol abuse, and other diseases such as asthma can make ARDS and ALI worse.

Signs and Symptoms of ARDS

It is very hard for oxygen to get into the bloodstream when the lungs are filled with fluid.  Air sacs filled with fluid may collapse. This can lead to the following signs and symptoms:

  • Difficult and fast breathing
  • Shortness of breath
  • Low blood pressure
  • Fast heart beat
  • Changes in awareness or difficulty concentrating

Usually, symptoms of ARDS or ALI begin within 2 days of the original illness or injury to the body.  ARDS often happens at the same time other organs fail.  When a doctor thinks a patient has ARDS, he or she may use these tests:

  • Chest x-rays to look for a pattern that is typical with ARDS
  • Measure blood gases  to check oxygen and carbon dioxide levels
  • Blood tests to find out the condition of other organs
  • Samples of blood and saliva (sputum) to look for possible infections


The first goal of treatment for ARDS is to support the failing lungs and other organs.  This gives them time to heal.  Treatment includes giving the lungs more oxygen and adding helpful pressure to the lungs.  In order to provide this treatment, a breathing tube is placed in the mouth.  Then, the patient is placed on a machine to help with breathing, called a ventilator.  If the ventilator is needed longer than 1 to 2 weeks, the breathing tube is usually replaced with a tracheostomy (trake-e-OST-o-mee) tube.  This tube is more comfortable.

At the same time, the original problem that led to ARDS must be treated.  Medicine may be given to help with comfort and rest. Medicine may also be given to relax muscles in the body.  All of this will help the lungs deliver oxygen to the body, save energy, and make it easier for the breathing machine to provide support.

Some patients may need other medicine to treat infection, low blood pressure, or inflammation, or to prevent stomach bleeding and blood clots.

Food (nutrition) is an important part of the treatment for ARDS.  Because a person can’t swallow with a breathing tube in place, he or she gets nutrition through a feeding tube.


The increased pressure needed to fill the lungs with air may cause more damage to the already weak lungs.  Infection of the lungs, called pneumonia, may develop.  The kidneys, liver, brain, heart, blood, and immune systems also may be affected. Treatment may get complicated as several problems are managed at the same time.

Steps to Healing and Permanent Effects

ARDS usually involves 3 steps as it progresses.

  • Step 1: Fluid collects in the lungs a few days after a serious illness or injury.
  • Step 2: The body tries to heal from the injury. This stage may last several weeks.
  • Step 3: The lungs heal slowly over many months. However, the time it takes to recover is different for each patient.

ARDS is a serious illness. It can be very hard on family and friends.  A person with ARDS may be in intensive care and the hospital for a long time.  Unfortunately, even with treatment, ARDS often causes damage to the lungs or other organs that will never heal.  Some patients get better quickly.  Others have a longer, slower recovery period with many setbacks. Some patients may not recover.

Additional Resources

The American Lung Association
61 Broadway, 6th Floor
New York, NY 10006
Phone: 1-800-548-8252

National Heart, Lung, and Blood Institute
NHLBI Health Information Center
PO Box 30105
Bethesda, MD 20824-0105
Phone: 301-592-8573

                                                                                                                                            Reviewed 2011

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