by Scholten A
(Acute Respiratory Failure; Chronic Respiratory Failure)


Respiratory failure is a problem getting gases in and out of the blood. Oxygen helps the body work well. 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:

  • Low levels of oxygen in the blood
  • High levels of carbon dioxide in the blood
  • Both low oxygen levels and high carbon dioxide levels

This condition can be life-threatening.

There are two types of respiratory failure:

  • Acute—starts fast
  • Chronic—happens slowly over time
Oxygen Exchange in the Lungs
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Respiratory failure is caused by conditions or injuries that affect breathing. It may be due to:

  • Problems with lungs or airways
  • Problems with bones, muscles, or nerves that help breathing

Breathing problems make it hard for lungs to move oxygen to blood or remove carbon dioxide.

Risk Factors

Things that raise the risk of acute respiratory failure are:

  • Injuries to the lungs or chest
  • Drug or alcohol abuse
  • Stroke
  • Inhaling smoke or fumes
  • Severe head injury
  • Choking or drowning
  • Sudden illnesses

Things that raise the risk of chronic respiratory failure are:


Symptoms depend on the cause. They also depend on levels of oxygen and carbon dioxide in the blood.

Low oxygen levels can cause:

  • Problems breathing
  • Bluish color to the skin, lips, and fingernails
  • Sleepiness
  • Uneven heartbeats

A buildup of carbon dioxide can cause:

  • Fast breathing
  • Confusion


The doctor will ask about symptoms and past health. A physical exam will be done. The doctor will listen for lung sounds.

Tests will check oxygen and carbon dioxide levels in the blood. They include:

  • Blood tests
  • Oximetry—a small clip on the finger, toe, or ear, that measures oxygen in the blood

Images of the chest and lungs may be done—to look for causes or injuries.


The goal is to improve oxygen or carbon dioxide levels in the body. Treatment depends on how severe the condition is.

Acute Respiratory Failure

The acute type is often treated in a hospital. Steps may include:

Other care may be given. It may ease discomfort or treat some causes. The acute type often goes away once the injury or illness has healed.

Chronic Respiratory Failure

The chronic type needs long term care. Oxygen therapy and breathing support will help. Other options may be:

  • Home oxygen therapy— A machine or tank provides 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 keep the airway open during sleep. A mask gently pushes air into the airways. 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.

Management of lung illness can prevent or slow respiratory failure. Helpful steps are:

  • Not smoking
  • Getting advised vaccines


American Lung Association 

Centers for Disease Control and Prevention 


Health Canada 

The Lung Association 


Acute respiratory failure—approach to the patient. EBSCO DynaMed website. Available at: Accessed August 10, 2021.

Lamba TS, Sharara RS, et al. Pathophysiology and classification of respiratory failure. Crit Care Nurs Q. 2016;39(2):85-93.

Overview of respiratory failure. The Merck Manual Professional Edition. Available at: . Accessed August 10, 2021.

Respiratory failure. National Heart, Lung and Blood Institute website. Available at: . Accessed August 10, 2021.

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