What is oxygen therapy?

If you’re living with a lung condition, you may be offered oxygen therapy if your blood oxygen levels are low to reduce feelings of breathlessness and tiredness.

The air we breathe at sea level contains 21% oxygen. Oxygen is a gas vital to all the cells in our bodies. If you have a lung condition you may have low oxygen levels in your blood.

Why is oxygen therapy used?

If your blood oxygen levels are low, oxygen therapy will reduce your feelings of tiredness and breathlessness. However, there are many reasons for feeling breathless and tired, so it is very important to be assessed by a health care professional.

If you do have low blood oxygen levels, breathing in air with a higher concentration of oxygen can correct this. The supplementary oxygen will make you feel less breathless, less tired and able to do more, particularly if your breathlessness is worse when moving around.

If you are already on oxygen and have never been assessed, ask your GP to refer you to a specialist. The specialist will assess why you are breathless and check if you have low oxygen levels.

“It is great to feel you are not breathing through a straw. I am now able to be completely mobile, even to go to aqua physio and swimming.” 

- Jean, 67, who has COPD and uses oxygen over 15 hours a day

What is oxygen therapy?

There are several different kinds of oxygen therapy:

  • long term oxygen therapy (LTOT) - used to stabilise oxygen levels for at least 15 hours per day
  • nocturnal oxygen therapy (NOT) - used to improve oxygen levels during sleep
  • ambulatory oxygen therapy (AOT) - used to improve oxygen levels during activity
  • palliative oxygen therapy (POT) - used to manage severe intractable breathlessness
  • short-burst oxygen therapy (SBOT) - used to improve oxygen levels following a flare-up or exacerbation

Intermittent oxygen therapy is often indicated for people diagnosed with a restrictive lung condition. 

Obstructive and restrictive lung conditions

Obstructive and restrictive lung diseases share the same main symptom: shortness of breath when you exert yourself, but they result from different processes in your lungs.

In obstructive lung disease there is a narrowing of the airways inside your lungs and the air comes out more slowly than normal when breathing out. Your lungs never empty of air completely but more air stays in your lungs than normal after you breathe out.

Common obstructive lung diseases are:

If you have a restrictive lung disease, you cannot fill your lungs fully with air because your lungs are restricted from fully expanding. Restrictive lung conditions result in stiffness or a loss of elasticity in the lungs themselves.

The most common restrictive lung conditions are:

The amount of oxygen and the method of its delivery may be different depending on whether you have a restrictive or obstructive lung condition. People with obstructive lung disease often benefit from long term oxygen therapy (LTOT) whereas people with an interstitial lung disease such as IPF are better suited to intermittent oxygen therapy of variable rate according to activity level.

Please discuss your individual needs with your health care professional. It is important to remember that you may have both a restrictive and an obstructive lung condition so your oxygen prescription will reflect this.

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Last medically reviewed: February 2015. Due for review: February 2018

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.