If you’re breathless and it is due to falling oxygen levels, help may be at hand in the form of supplementary oxygen. Many people use oxygen like any other treatment: to improve their day to day life and make activities easier.

Breathing and oxygen

When you breathe in, air travels down your windpipe into your lungs. After absorbing the oxygen from the air, blood leaves the lungs and is carried to the heart. The blood is then pumped through your body to provide oxygen to the cells of your tissues and organs.

When cells use oxygen, carbon dioxide (CO2) is produced and transferred to the blood. Your blood then carries the CO2 back to your lungs and it is removed when you breathe out.


People with pulmonary fibrosis can often feel breathless. A build-up of scar tissue in your lungs – as with pulmonary fibrosis – restricts the transfer of oxygen from the tiny air sacs in your lungs into your blood. This causes low levels of oxygen in the blood. The use of supplementary oxygen can help.

There are other causes of breathlessness. It’s a good idea to have your breathlessness assessed by your local healthcare team. Find out more about breathlessness.

Oxygen saturation levels

Oxygen is carried around in your red blood cells by a molecule called haemoglobin. Oxygen saturation (SaO2) is a measure of how much oxygen the haemoglobin is carrying.

Low SaO2 means that the lungs are struggling to transfer oxygen into the blood. This is more likely to happen when you exert yourself because that is when blood is travelling faster through the lungs.

Assessing your oxygen levels

A pulse oximetry test uses a sensor placed on your fingertip or earlobe to measure your oxygen saturation. For someone who’s healthy, the normal blood oxygen saturation level will be 95–100%. If yours is 92% or less when you are resting, you should be referred for an assessment to see if supplementary oxygen is appropriate.

At the assessment, your oxygen levels will be measured at rest and when you walk. You may also have a blood gas analysis, where a small sample of blood is taken from your wrist, the inside of your elbow or your earlobe.

I was put on oxygen when my condition deteriorated. It enabled me to keep going and survive, allowing me to carry on with my life. After a short time in hospital I was allowed home after the installation of an oxygen concentrator and continued use of the portable concentrator when going out.
The oxygen, coupled with a pulmonary rehab course, helped me get back to my previous activity level. I now only use oxygen if I am doing anything strenuous.
Going out and about with my portable concentrator has shown me just how kind everyone is, especially in shops and supermarkets, and on public transport, where people don‘t hesitate to help.

Oxygen equipment

There are a number of ways to get supplementary oxygen, all of which need to be prescribed specifically for you. You may have different oxygen prescriptions for each device. Your local healthcare team will explain to you how you should use your oxygen.

Don’t forget that oxygen increases fire risk. Please do not smoke using oxygen and keep away from naked flames. Store your oxygen in a safe place.

Find the UK's oxygen suppliers

Home oxygen

The oxygen concentrator is a small machine that is delivered to your home. It is powered by electricity which filters the air allowing only oxygen to reach you through either nasal cannula or a mask.

It can be used 24 hours a day, seven days a week and is regularly serviced by the oxygen contractor. You will be reimbursed for electricity used. You will also be given a large back-up cylinder for use in an emergency such as a power cut.

Portable or ambulatory oxygen

Oxygen cylinders are small and lightweight for use outside the home. They may be fitted with an oxygen conserver that will deliver a pulse dose of oxygen only when you breathe in. This allows the cylinder to last longer. If you need continuous oxygen you will be given a cylinder without a conserver.

You may be given several cylinders at a time for use outside the home – you just telephone the oxygen company once they are empty for your replacements. You will be supplied with a back pack or trolley for transporting your oxygen cylinder, or you can use your own trolley to transport your oxygen.

If you are using a lot of ambulatory oxygen at higher flow rates, your oxygen assessor may recommend that you use liquid oxygen. Liquid oxygen is usually delivered at regular intervals in the form of a large reservoir unit and a smaller device that you fill yourself from the reservoir unit. Your oxygen supplier will show you how to use this. You will need to store your reservoir tank on the ground floor or in a garage. There are special storage instructions associated with the storage and use of liquid oxygen which you will need to consider. You will have one or two ambulatory cylinders that you can fill yourself before you go out.

Pulmonary rehab and oxygen

People who use oxygen will be assessed to see if they need it during pulmonary rehabilitation. Oxygen may help to increase how much exercise you can do. If you have been prescribed ambulatory oxygen for exercise, don’t forget to take the device along to the class.

Chair of APF Steve Jones told us, “I found ambulatory oxygen really important in staying fit and feeling positive. With a cylinder of oxygen, I could get out and do my daily walk and do my pulmonary rehabilitation exercises. Although I didn’t know it at the time, it kept me fit enough to be candidate for a lung transplant.

“I was reluctant to start using oxygen because it meant accepting that my symptoms were getting worse and the disease was progressing. It felt like I was ‘giving in’. In retrospect, this was foolish. I wish I had started on ambulatory oxygen much earlier than I did."

Holidaying with oxygen

If you need oxygen at home, you will need to arrange a supply at your holiday destination. Find out more going on holiday with oxygen.

Watch our webinar on oxygen therapy

Information provided by Action for Pulmonary Fibrosis (APF) is not a substitute for professional medical advice. It’s intended as general information only. APF is not responsible for any errors or omissions or for any loss or damage suffered by users resulting from the information published on actionpf.org.

Further information for carers:

Your essential caring guide (PDF)
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