We use strictly necessary cookies to make our site work. We would also like to set optional cookies (analytical, functional and YouTube) to enhance and improve our service. You can opt-out of these cookies. By clicking “Accept All Cookies” you can agree to the use of all cookies.

Cookies Statement and Privacy Statement

Respiratory Distress Syndrome (Acute)

Page last reviewed: 13/07/2011

Respiratory distress syndrome is a potentially life-threatening medical condition where the lungs cannot provide enough oxygen for the rest of the body.

Symptoms of respiratory distress syndrome include:

  • blue-coloured lips, fingers and toes
  • rapid, shallow breathing
  • rapid heartbeat

Types of respiratory distress syndrome

There are two main types of respiratory distress syndrome:

Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) mainly affects adults. It occurs when a person's lungs become seriously damaged and filled with fluid, affecting their ability to breathe in oxygen.

The damage can occur because of:

  • an injury to the lungs or a lung infection, such as pneumonia or flu
  • an infection that spreads from another part of the body into the blood and then into the lungs (this is a common cause of ARDS)

ARDS mainly affects people over 75 years of age. It's estimated that only 1 in every 6,000 people will develop the condition in each year.

Read more about the causes of respiratory distress syndrome.

Treatment and outlook

ARDS is treated using a ventilator to assist breathing while the underlying cause is treated. As people with ARDS are usually very ill in the first place, there is a high risk of complications, which lead to death in a third of cases. 

Read more about treating respiratory distress syndrome. 

Page last reviewed: 13/07/2011

Acute respiratory distress syndrome

It is rare for the symptoms of acute respiratory distress syndrome (ARDS) to develop on their own. ARDS usually develops as a complication of a serious, existing health condition (see causes of respiratory distress syndrome). By the time the symptoms of ARDS begin, most people have already been admitted to hospital for another reason.

Symptoms of ARDS include:

  • blue-coloured lips, fingers and toes
  • rapid, shallow breathing
  • breathing that becomes increasingly laboured and difficult
  • rapid heartbeat
  • tiredness, which is usually followed by drowsiness or confusion

Page last reviewed: 13/07/2011

Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) develops if the lungs become very inflamed due to a severe infection or injury. The inflammation causes the air sacs to collapse and fluid from nearby blood vessels to leak into the lungs.

Over time, the lungs will become so full of fluid that breathing becomes increasingly difficult. If it is not treated, ARDS will eventually cause a total loss of lung function and will lead to death.

The lungs may become inflamed due to:

  • pneumonia
  • flu (both seasonal flu and swine flu can trigger ARDS in vulnerable people)
  • heart failure 
  • severe chest injury
  • smoke inhalation
  • accidental inhalation of toxic chemicals
  • drug overdose
  • near drowning
  • a piece of food or another object accidentally falling down into the lungs
  • acute pancreatitis, where inflammation of the pancreas can spread throughout the body

Lung inflammation may occur following an infection that has spread through the blood to affect the whole body.

Inflammation can also occur if you fracture one of your long bones, such as the thigh bone. If fat particles are released, they can travel up into your lungs.

Page last reviewed: 13/07/2011

 Acute respiratory distress syndrome

A physical examination and blood tests and a pulse oximetry test are used to measure the amount of oxygen and carbon dioxide in the blood and lungs. A chest X-ray may also be used to check the condition of the lungs.

Page last reviewed: 13/07/2011

Acute respiratory distress syndrome

If you develop acute respiratory distress syndrome (ARDS), you will probably be admitted to an intensive care unit (ICU) and put on a ventilator to assist your breathing. In some cases, it may be possible to use an oxygen mask to supply you with oxygen.

If you have severe ARDS, a tube will be inserted down your throat and into your lungs through which oxygen is pumped. Fluids and nutrients will be supplied through a tube in your vein.

It will also be necessary to treat the causes of ARDS. For example, if it was caused by an infection, you may be prescribed antibiotics to help fight the infection.

The amount of time you need to spend in hospital will depend on your individual circumstances and the cause of ARDS. Most people respond well to treatment within 72 hours, although it may take several weeks or months before you are well enough to leave hospital.

Page last reviewed: 13/07/2011

Abnormal lung function

Many people with acute respiratory distress syndrome (ARDS) recover normal lung function within six months. However, in some cases, the lungs may become permanently damaged which can lead to symptoms such as:

  • extreme tiredness
  • chest pain
  • shortness of breath, particularly when being physically active

If you have permanent damage to your lungs, you will be prescribed medication, such as bronchodilators, to help with your breathing. In the most severe cases of ARDS, oxygen therapy, such as using a portable oxygen tank to help with breathing, may be required.

Muscle weakness

Muscle weakness affects most people recovering from an episode of ARDS. This is because spending several weeks in bed and on a ventilator can result in a rapid weakening of the muscles.

Once you are discharged from hospital, it is likely that you will require a course of physical therapy, such as strengthening exercises, to regain your muscle strength.

Mental functions

In many cases of ARDS, brain damage can occur due to the brain being starved of oxygen. This can lead to long-term problems with a person's mental functions, such as memory and learning.

Common problems in people recovering from ARDS include:

  • memory problems, such as difficulty recalling certain words or remembering people's names
  • difficulty concentrating
  • low attention span
  • problems doing complex mental tasks, such as mental arithmetic


An episode of ARDS can be traumatic and frightening, and the recovery process can sometimes be stressful and frustrating.

As a result, people who are recovering from ARDS often become depressed. It's estimated that a quarter of people recovering from ARDS have moderate to severe depression.

Signs of depression include:

  • feeling down or hopeless for extended periods of time
  • having little interest or pleasure in doing things you usually enjoy

Contact your GP for advice if you think you may be depressed.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

Browse Health A-Z