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What Is Oxygen Therapy?

Oxygen therapy is a treatment that provides you with extra oxygen, a gas that your body needs to work well. Normally, your lungs absorb oxygen from the air. However, some diseases and conditions can prevent you from getting enough oxygen.

Oxygen therapy may help you function better and be more active. Oxygen is supplied in a metal cylinder or other container. It flows through a tube and is delivered to your lungs in one of the following ways:

  • Through a nasal cannula, which consists of two small plastic tubes, or prongs, that are placed in both nostrils.
  • Through a face mask, which fits over your nose and mouth.
  • Through a small tube inserted into your windpipe through the front of your neck. Your doctor will use a needle or small incision (cut) to place the tube. Oxygen delivered this way is called transtracheal oxygen therapy.

Oxygen therapy can be done in a hospital, another medical setting, or at home. If you need oxygen therapy for a chronic (ongoing) disease or condition, you might receive home oxygen therapy.

Overview

To learn how oxygen therapy works, it helps to understand how your respiratory system works. This system is a group of organs and tissues that help you breathe. The respiratory system includes the airways and lungs.

The airways carry oxygen-rich air to your lungs. They also carry carbon dioxide (a waste gas) out of your lungs.

Air enters your body through your nose or mouth, which moistens and warms the air. The air then travels through your voice box and down your windpipe. The windpipe divides into two tubes called bronchi that enter your lungs.

Within your lungs, your bronchi branch into thousands of smaller, thinner tubes called bronchioles (BRONG-ke-ols). These tubes end in bunches of tiny round air sacs called alveoli (al-VEE-uhl-eye).

Each of the air sacs is covered in a mesh of tiny blood vessels called capillaries (KAP-ih-lare-ees). The capillaries connect to a network of arteries and veins that move blood throughout your body.

When air reaches the air sacs, the oxygen in the air passes through the air sac walls into the blood in the capillaries.

The oxygen-rich blood then travels to the heart through the pulmonary vein and its branches. The heart pumps the oxygen-rich blood to your organs. (For more information, go to the Health Topics How the Lungs Work article.)

Certain acute (short-term) and chronic (ongoing) diseases and conditions can affect the transfer of oxygen from the alveoli into the blood. Examples include pneumonia (nu-MO-ne-ah) and COPD (chronic obstructive pulmonary disease).

Your doctor will decide whether you need oxygen therapy based on the results of tests, such as an arterial blood gas test and a pulse oximetry test. These tests measure how much oxygen is in your blood. A low oxygen level is a sign that you need oxygen therapy.

Oxygen is considered a medicine, so your doctor must prescribe it.

Outlook

Oxygen therapy helps many people function better and be more active. It also may help:

  • Decrease shortness of breath and fatigue (tiredness)
  • Improve sleep in some people who have sleep-related breathing disorders
  • Increase the lifespan of some people who have COPD

Although you may need oxygen therapy long term, it doesn't have to limit your daily routine. Portable oxygen units can make it easier for you to move around and do many daily activities. Talk with your doctor if you have questions about whether certain activities are safe for you.

A home equipment provider will work with you to make sure you have the supplies and equipment you need. Trained staff also will show you how to use the equipment correctly and safely.

Oxygen therapy generally is safe, but it can pose a fire hazard. To use your oxygen safely, follow the instructions you receive from your home equipment provider.




Other Names for Oxygen Therapy

  • Oxygen
  • Supplemental oxygen



Who Needs Oxygen Therapy?

Your doctor may recommend oxygen therapy if you have a low blood oxygen level. Normally, your lungs absorb oxygen from the air and transfer it into your bloodstream.

Some acute (short-term) and chronic (ongoing) diseases and conditions can prevent you from getting enough oxygen.

Acute Diseases and Conditions

You may receive oxygen therapy if you're in the hospital for a serious condition that prevents you from getting enough oxygen. Once you've recovered from the condition, the oxygen will likely be stopped.

Some diseases and conditions that may require short-term oxygen therapy are:

  • Severe pneumonia. Pneumonia is an infection in one or both of the lungs. If severe, the infection causes your lungs' air sacs to become very inflamed. This prevents the air sacs from moving enough oxygen into your blood.
  • Severe asthma attack. Asthma is a lung disease that inflames and narrows the airways. Most people who have asthma, including many children, can safely manage their symptoms. But if you have a severe asthma attack, you may need hospital care that includes oxygen therapy.
  • Respiratory distress syndrome (RDS) or bronchopulmonary dysplasia (BPD) in premature babies. Premature babies may develop one or both of these serious lung conditions. As part of their treatment, they may receive extra oxygen through a nasal continuous positive airway pressure (NCPAP) machine or a ventilator (VEN-til-a-tor), or through a tube in the nose.

Chronic Diseases and Conditions

Long-term home oxygen therapy might be used to treat some diseases and conditions, such as:

  • COPD (chronic obstructive pulmonary disease). This is a progressive disease in which damage to the air sacs prevents them from moving enough oxygen into the bloodstream. "Progressive" means the disease gets worse over time.
  • Late-stage heart failure. This is a condition in which the heart can't pump enough oxygen-rich blood to meet the body's needs.
  • Cystic fibrosis (CF). CF is an inherited disease of the secretory glands, including the glands that make mucus and sweat. People who have CF have thick, sticky mucus that collects in their airways. The mucus makes it easy for bacteria to grow. This leads to repeated, serious lung infections. Over time, these infections can severely damage the lungs.
  • Sleep-related breathing disorders that lead to low levels of oxygen in the blood during sleep, such as sleep apnea.



How Does Oxygen Therapy Work?

Oxygen therapy provides you with extra oxygen, a gas that your body needs to work well. Oxygen comes in different forms and can be delivered to your lungs in several ways.

Oxygen Therapy Systems

Oxygen is supplied in three forms: as compressed gas, as liquid, or as a concentrated form taken from the air.

Compressed oxygen gas is stored under pressure in metal cylinders. The cylinders come in many sizes. Some of the cylinders are small enough to carry around. You can put one on a small wheeled cart or in a shoulder bag or backpack.

Liquid oxygen is very cold. When released from its container, the liquid becomes gas. Liquid oxygen is delivered to your home in a large container. From this container, smaller, portable units can be filled.

The advantage of liquid oxygen is that the storage units need less space than compressed or concentrated oxygen. However, liquid oxygen costs more than the other forms of oxygen. Also, it evaporates easily, so it doesn't last for a long time.

Oxygen concentrators filter out other gases in the air and store only oxygen. Oxygen concentrators come in several sizes, including portable units.

Oxygen concentrators cost less than the other oxygen therapy systems. One reason is because they don't require oxygen refills. However, oxygen concentrators are powered by electricity. Thus, you'll need a backup supply of oxygen in case of a power outage.

Delivery Devices

Most often, oxygen is given through a nasal cannula. A nasal cannula consists of two small plastic tubes, or prongs, that are placed in both nostrils.

To help hold the cannula in place, you can put the longer ends of it over your ears or attach them to a special kind of eyeglass frame that helps hide the tubing. The tubing then comes around the back of your ears and under your chin, where it joins together. From there, it's attached to the tube from the oxygen container.

Nasal Cannula and Portable Oxygen Container

The image shows how a nasal cannula and portable oxygen container are attached to a patient.

The image shows how a nasal cannula and portable oxygen container are attached to a patient.

You might use a face mask instead of a nasal cannula. The mask fits over your mouth and nose. This method mainly is used if you need a high flow rate of oxygen or if your nose is clogged from a cold.

The face mask is held in place with a strap that goes around your head or with tubes that fit around your ears. The oxygen is delivered through a tube that attaches to the front of the mask.

Oxygen also can be delivered through a small tube inserted into your windpipe through the front of your neck. Your doctor will use a needle or small incision (cut) to place the tube. Oxygen delivered this way is called transtracheal oxygen therapy.

If you're getting transtracheal oxygen therapy, you'll need to have a humidifier attached to your oxygen system. This is because the oxygen doesn't pass through your nose or mouth like it does with the other delivery systems. A humidifier adds moisture to the oxygen and prevents your airways from getting too dry.

Oxygen also can be delivered through machines that support breathing, such as CPAP (continuous positive airway pressure) devices or ventilators.




What To Expect Before Oxygen Therapy

During an emergency—such as a serious accident, possible heart attack, or other life-threatening event—you might be started on oxygen therapy right away.

Otherwise, your doctor will decide whether you need oxygen therapy based on test results. An arterial blood gas test and a pulse oximetry test can measure the amount of oxygen in your blood.

For an arterial blood gas test, a small needle is inserted into an artery, usually in your wrist. A sample of blood is taken from the artery. The sample is then sent to a laboratory, where its oxygen level is measured.

For a pulse oximetry test, a small sensor is attached to your fingertip or toe. The sensor uses light to estimate how much oxygen is in your blood.

If the tests show that your blood oxygen level is low, your doctor may prescribe oxygen therapy. In the prescription, your doctor will include the number of liters of oxygen per minute that you need (oxygen flow rate). He or she also will include how often you need to use the oxygen (frequency of use).

Frequency of use includes when and for how long you should use the oxygen. Depending on your condition and blood oxygen level, you may need oxygen only at certain times, such as during sleep or while exercising.

If your doctor prescribes home oxygen therapy, he or she can help you find a home equipment provider. The provider will give you the equipment and other supplies you need.




What To Expect During Oxygen Therapy

During an emergency—such as a serious accident, possible heart attack, or other life-threatening event—you might be started on oxygen therapy right away.

While you're in the hospital, your doctor will check on you to make sure you're getting the right amount of oxygen. Nurses or respiratory therapists also may assist with the oxygen therapy.

If you're having oxygen therapy at home, a home equipment provider will help you set up the oxygen therapy equipment at your house.

Trained staff will show you how to use and take care of the equipment. They'll supply the oxygen and teach you how to safely handle it.

Because oxygen poses a fire risk, you'll need to take certain safety steps. Oxygen isn't explosive, but it can worsen a fire. In the presence of oxygen, a small fire can quickly get out of control. Also, the cylinder that compressed oxygen gas comes in can explode if it's exposed to heat.

Your home equipment provider will give you a complete list of safety steps that you'll need to follow at home and in public. For example, while on oxygen, you should:

  • Never smoke or be around people who are smoking
  • Never use paint thinners, cleaning fluids, gasoline, aerosol sprays, and other flammable materials
  • Stay at least 5 feet away from gas stoves, candles, and other heat sources

When you're not using the oxygen, keep it in a large, airy room. Never store compressed oxygen gas cylinders and liquid oxygen containers in small, enclosed places, such as in closets, behind curtains, or under clothes.

Oxygen containers let off small amounts of oxygen. These small amounts can build up to harmful levels if they're allowed to escape into small spaces.




What Are the Risks of Oxygen Therapy?

Oxygen therapy can cause complications and side effects. These problems might include a dry or bloody nose, skin irritation from the nasal cannula or face mask, fatigue (tiredness), and morning headaches.

If these problems persist, tell your doctor and home equipment provider. Depending on the problem, your doctor may need to change your oxygen flow rate or the length of time you're using the oxygen.

If nose dryness is a problem, your doctor may recommend a nasal spray or have a humidifier added to your oxygen equipment.

If you have an uncomfortable nasal cannula or face mask, your home equipment provider can help you find a device that fits better. Your provider also can recommend over-the-counter gels and devices that are designed to lessen skin irritation.

Complications from transtracheal oxygen therapy can be more serious. With this type of oxygen therapy, oxygen is delivered through a tube inserted into your windpipe through the front of your neck.

With transtracheal oxygen therapy:

  • Mucus balls might develop on the tube inside the windpipe. Mucus balls tend to form as a result of the oxygen drying out the airways. Mucus balls can cause coughing and clog the windpipe or tube.
  • Problems with the tube slipping or breaking.
  • Infection.
  • Injury to the lining of the windpipe.

Proper medical care and correct handling of the tube and other supplies may reduce the risk of complications.

Other Risks

In certain people, oxygen therapy may suppress the drive to breathe, affecting how well the respiratory system works.  This is managed by adjusting the oxygen flow rate.

Oxygen poses a fire risk, so you'll need to take certain safety steps. Oxygen itself isn't explosive, but it can worsen a fire. In the presence of oxygen, a small fire can quickly get out of control. Also, the cylinder that compressed oxygen gas comes in might explode if exposed to heat.

Your home equipment provider will give you a complete list of safety steps you'll need to take at home and when out in public.

For example, when you're not using the oxygen, keep it in an airy room. Never store compressed oxygen gas cylinders and liquid oxygen containers in small, enclosed places, such as in closets, behind curtains, or under clothes.

Oxygen containers let off small amounts of oxygen. These small amounts can build up to harmful levels if they're allowed to escape into small spaces.




Living With Oxygen Therapy

Oxygen therapy helps many people function better and be more active. It also may help:

  • Decrease shortness of breath and fatigue (tiredness)
  • Improve sleep in some people who have sleep-related breathing disorders
  • Increase the lifespan of some people who have COPD (chronic obstructive pulmonary disease)

Although you may need oxygen therapy continuously or for long periods, it doesn't have to limit your daily routine. Portable oxygen units can make it easier for you to move around and do many daily activities. Talk with your doctor if you have questions about whether certain activities are safe for you.

Portable oxygen units also can make it easier for you to travel. Often, the rules for traveling with oxygen vary depending on the transportation carrier (for example, the airline or bus company). If you need oxygen while traveling, plan in advance. Contact your transportation carrier to find out their specific rules.

Also, talk with your doctor and home equipment provider if you're planning to travel. They can help you plan for your oxygen needs and fill out any required medical forms.

Ongoing Care

To make sure you're getting the full benefits of oxygen therapy, visit your doctor regularly. Your doctor can check your progress and adjust your oxygen therapy as needed.

Never change the amount of oxygen you're taking or adjust the flow rate of your oxygen on your own. Discuss any problems or side effects with your doctor first. He or she may recommend adjusting your treatment.

Talk with your doctor about when you should contact him or her or seek emergency medical care. Your doctor can advise you about what to do if you have:

  • Increased shortness of breath, wheezing, or other changes from your usual breathing.
  • Fever, increased mucus production, or other symptoms of an infection.
  • A blue tint to your lips or fingernails. This is a sign that your body isn't getting enough oxygen.
  • Confusion, restlessness, or more anxiety than usual.

During an emergency, go to your nearest hospital emergency room or call 9–1–1. You might want to wear a medical ID bracelet or necklace to alert others to your medical needs.




Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. For example, this research has helped evaluate treatments and therapies for many diseases and conditions.

The NHLBI continues to support research on various treatments, including oxygen therapy. For example, the NHLBI is studying how well long-term oxygen therapy works for people who have COPD with moderately low oxygen levels at rest or very low oxygen levels during exercise.

Much of the NHLBI's research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions.

For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you may gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to oxygen therapy, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.




Links to Other Information About Oxygen Therapy

NHLBI Resources

Non-NHLBI Resources

Clinical Trials

 
February 24, 2012 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.

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