What is oxygen therapy and how does it work?

People with PH need their heart and lungs to work much harder to get the oxygen they need. PH causes them to have too little oxygen in their blood while at rest or during exercise. This can lead to symptoms, such as tiredness and breathlessness. Oxygen therapy (supplementary oxygen) increases the amount of oxygen in the blood, and so can reduce these symptoms. Oxygen therapy may also improve concentration and the ability to do everyday tasks, such as walking short distances. Oxygen therapy can be an important addition to treatment for PH. As well as increasing the amount of oxygen in the blood, oxygen has the additional benefit that it is a vasodilator. This means that it helps to relax the arteries in the lungs, which can reduce the pressure in the pulmonary artery.

How do you get oxygen therapy?

For many people with PH, supplementary oxygen is not always helpful or even needed. If you need to have oxygen therapy at home, a member of your PH team will work out with you how much oxygen you will need, how long you will need it for, and will discuss the different ways in which you can get oxygen at home. You will need to fill in a consent form. This is because, in order to provide you with the equipment and the oxygen in your home, some information about your needs will have to be shared with other organisations in (or working with) the NHS.

You will also have to give permission for an engineer to visit your home now and then. This is to:
• Install the equipment and explain how to use it.
• Deliver new supplies of oxygen.
• Check your equipment every so often, especially if you are worried it is not working properly.

A home oxygen order form (HOOF) will be completed by a member of your PH team on your behalf. This is a bit like a prescription, and tells the company that will deliver your oxygen and equipment what your needs are.

What are the different types of oxygen service?

Oxygen can be obtained from:
• Compressed oxygen cylinders.
• Liquid oxygen in cylinders.
• An oxygen concentrator machine, which extracts oxygen from the air.

All of these methods are paid for by the NHS. If you use oxygen for short periods to relieve attacks of breathlessness you will probably be prescribed oxygen cylinders. For those people who would benefit from oxygen for a significant number of hours a day, it is normally taken while asleep. For these people, oxygen concentrator machines are more convenient and cost effective.

Oxygen concentrator
An oxygen concentrator is a machine about 2 feet square and 2.5 feet (75cm) high. It plugs into the ordinary household electricity supply. It filters oxygen from the air in the room, and this oxygen is then delivered by plastic tubing to a mask or through soft tubes in your nose (called cannulae). Long tubing can be fixed around the floor or skirting board, with two points where the user can ‘plug in’ to the oxygen supply. When the oxygen concentrator machine is installed, the engineer or nurse will discuss with you the length of tubing you will need. It is possible to have an additional outlet in another room. This allows you to locate the oxygen concentrator away from where you sleep. This can be useful since they make a noise while working. The engineer will explain to you, or to a friend or relative, how to use it and will be able to answer any questions you may have. A ‘back-up’ cylinder of oxygen is also provided in case of breakdown and regular maintenance visits will be made to make sure that the concentrator is always operating correctly.

Oxygen cylinders
When you use an oxygen cylinder, you breathe oxygen in either through a mask, or through cannulae in your nose. All of this will be explained to you carefully when you first use oxygen.

Liquid oxygen
Portable tanks containing oxygen compressed into liquid form can contain more oxygen than when it is uncompressed. The tanks can be lighter, too. Ask your oxygen supplier for details.

Portable oxygen (also called ambulatory oxygen)
If you are using oxygen for PH in the home, you may also want a small oxygen cylinder to use outside. It is important that you discuss this with a member of your PH team and are fully assessed to see whether portable oxygen is likely to be helpful. When full these portable oxygen cylinders weigh about 5lbs (2.5kg; about the same as a big bag of sugar) and hold just under two hours of oxygen at two litres per minute. It is also possible to have semiportable oxygen cylinders. These cylinders are heavier and not really suitable for carrying far but do help you get out of the house.

Portable oxygen concentrators
There are some very good portable oxygen concentrators available, but unfortunately they have to be purchased privately and are not available on prescription. Currently, they cost around £2500–£3000, so are not cheap. These portable concentrators can run for a number of hours on a rechargeable battery or often through an in-car charger. Ask advice first before taking the plunge and purchasing one of these machines. The PHA UK are happy to help with pointing you in the right direction and can give practical and independent advice.

Oxygen conservers
Once turned on, oxygen cylinders usually release a constant flow of oxygen whether the user is inhaling or not. An oxygen conserver changes the oxygen flow according to each breath. This eliminates oxygen wastage so that the cylinder lasts many times longer than with a continuous flow system.

Oxygen humidifiers
For people requiring oxygen at flow rates higher than 4L/min, an oxygen humidifier can be added. This is a simple attachment that adds water vapour to the oxygen you inhale, to prevent the oxygen from drying out your nasal passages.

Travelling with oxygen
It is important to discuss travel plans, especially those that involve flying, with your PH team or GP before booking your holiday. With planning, oxygen can be arranged at many of today’s holiday destinations but forward planning is a must.


“We give (people with PH) oxygen to help improve their symptoms and quality of life. Many patients ask me if oxygen is addictive or worry that if they start it they will get used to it and the effect will wear off – but I always reassure them this is not the case.” Dr. Luke Howard, Consultant Respiratory Physician