Respiratory Failure



Respiratory failure is a problem getting gases in and out of the blood. Oxygen is needed for the body to work well. Low levels can affect active organs like the heart and brain. Carbon dioxide is a waste product made in the body. It needs to pass out of the body through the lungs. Respiratory failure may be:

  • Hypoxemic respiratory failure–low levels of oxygen in the blood
  • Hypercapnic respiratory failure–high levels of carbon dioxide in the blood
  • Combination of low oxygen levels and high carbon dioxide levels

Acute respiratory failure starts fast. It often happens after an injury or illness. It may pass once the cause has cleared.

Chronic respiratory failure happens slowly over time. It is often the result of a lung illness. This type of failure often needs lifelong support.

Oxygen Exchange in the Lungs
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Normal breathing pulls oxygen in and pushes carbon dioxide out. A second gas exchange happens inside the lungs. Gas passes through lung tissue into or out of small blood vessels of the lungs. Respiratory failure happens with:

  • Problems moving air with each breath. It may be caused by:
    • Lung disease or conditions
    • Blockage of airway
    • Injuries to the chest or ribs
    • Muscles or nerves that are not working well
    • Problems of the spine that make it hard to fully open the chest, such as scoliosis
  • Problem moving gas across lung tissue to blood vessels. Can be caused by:
    • Lung disease or conditions
    • Trauma or illness
    • Air sacs that are blocked by fluids, harmful fumes or smoke
    • Brain damage, stroke, or drug or alcohol overdose that slows signals to breathe

Risk Factors

The risk of chronic failure is higher in people with certain chronic conditions or diseases such as:

  • Chronic obstructive pulmonary disease ( COPD ) which includes emphysema and chronic bronchitis
  • Stroke
  • Spinal cord injuries
  • Muscular dystrophy
  • Scoliosis
  • Chronic pneumonia
  • Pulmonary embolism
  • Cystic fibrosis
  • Severe asthma
  • Amyotrophic lateral sclerosis

Acute failure is often caused by trauma to lungs, chest, or brain which may occur with:

  • Inhaling smoke
  • Blow to chest and ribs
  • Drug or alcohol abuse
  • Stroke
  • Severe head injury
  • Choking
  • Drowning
  • Collapsed lung
  • Trauma or sudden illnesses



Low oxygen levels can cause:

  • Shortness of breath
  • Feeling like you’re out of breath even at rest
  • Bluish color on the skin, lips, and fingernails
  • Loss of consciousness
  • Irregular heartbeats

A buildup of carbon dioxide in the blood can cause:

  • Rapid breathing
  • Confusion


You will be asked about your symptoms and past health. A physical exam will be done. Symptoms and sounds of the lungs will suggest a lung problem.

Oxygen and carbon dioxide levels in the blood can be measured by:

  • Blood tests
  • Oximetry—small clip on your finger that can measure oxygen in the blood with a light

Images of the chest and lungs may also be taken. It will show signs of possible causes or injuries.



The goal of treatment is to improve oxygen levels inthe body. Exact steps will depend on the severity of the failure and overall health.

Acute Failure

Acute failure is often treated in a hospital. Intensive care is often needed. Steps may include:

  • Oxygen therapy—oxygen is passed through tubes into the nose or mouth. It will increase oxygen in the lungs. This will increase the amount of oxygen that can reach the body.
  • Mechanical ventilation—machine that helps your breathe. It will move air into the lungs until you can breathe well on your own again.

Other supportive care may be given. It may ease discomfort or treat some causes. This type of failure often goes away once the injury or illness has healed.

Chronic Respiratory Failure

Chronic failure will need long term care. Oxygen therapy and breathing support will help. Steps that may be needed include:

  • Home oxygen therapy. A machine or tank can provide oxygen at home. Smaller units can be taken outside the home. Oxygen may only be needed during activity or 24 hours per day.
  • Sleep support. A machine can help to keep the airway open during sleep. A mask gently pushes air into the airways. It helps keep the airways open and increases the amount of air in the lungs. Certain sleep positions or special beds may also ease breathing.
  • Mechanical ventilation may be needed if breathing is too weak.


There are no steps to prevent respiratory failure due to an accident.

Careful management of lung illness can prevent or delay respiratory failure. Steps that may help include:

  • If you smoke , talk to your doctor about ways to quit.
  • Get any recommended vaccinations. Pneumonia and flu vaccines are important for anyone with lung problems.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (Acute Respiratory Failure; Chronic Respiratory Failure)


American Lung Association 

Centers for Disease Control and Prevention 


Health Canada 

The Lung Association 


Explore respiratory failure. National Heart, Lung and Blood Institute website. Available at: Accessed February 12, 2019.

Overview of respiratory failure. The Merck Manual Professional Edition. Available at: Updated November 2013. Accessed February 12, 2019.