Oxygen therapy refers to breathing a high level of oxygen for a short time to correct a lack of oxygen in the tissues of the body. To raise the level of oxygen in damaged tissues, pure (100%) oxygen can be breathed with a tight fitting mask, but because oxygen is poorly soluble in blood it is also necessary to use a higher pressure. Individuals receiving oxygen therapy therefore need to sit in a pressure chamber, known as a barochamber.

These are built of steel and accommodate between one and 4 people . Barochambers are pressurised up to twice normal atmospheric pressure. The pressure inside is increased by using compressed air, and oxygen is provided by a built-in breathing system. This is exactly the same technology used in pressurised commercial aircraft. Anyone can access the therapy – a referral from a GP or consultant is not required, and the oxygen therapy is administered by trained operators.