Hyperbaric comes from the Greek where “hyper” means more and “baric” relates to pressure. This amounts to “more pressure.” Hyperbaric Oxygen Therapy allows a patient to absorb up to 4 times the normal amount of oxygen. This increases the oxygenation of all organs, tissues, and body fluids. It is the pressure of the chamber that allows for the much greater absorption of the oxygen provided. ? Breathing 100% pure oxygen outside the chamber will not significantly increase your oxygen uptake by the cells at all. When a patient is in the chamber, the increased pressure causes the blood plasma, and other liquids of the body, to absorb much larger quantities of oxygen, greatly increasing oxygen uptake by the cells, tissues, glands, organs, brain, and all fluids of the body. This oxygen can then be utilized by the body for vital functions. That really is how hyperbaric oxygen works.