Hyperbaric Oxygen Therapy is the breathing of oxygen while under pressures exceeding 1 atmosphere (1 atm), thus enhancing the amount of oxygen that can be dissolved in the blood and body tissues. When a patient is given oxygen under pressure, haemoglobin is saturated, but the blood can be hyper oxygenated by dissolving oxygen within the plasma. Normally most oxygen carried in the blood is bound to haemoglobin, which is 97% saturated at standard pressure. Some oxygen, however, is carried in solution, and this portion is increased under hyperbaric conditions. Because the oxygen is in solution, it can access parts of the body where red blood cells may not be able to reach and can also provide tissue oxygenation in the areas where there is impaired haemoglobin concentration or function. As a result of this process, damaged or diseased parts of the body can be healed due to receiving oxygen where they would be unable to do so at standard atmospheric pressure.