Hyperbaric medicine, also known as hyperbaric oxygen therapy, increases the amount of oxygen in the blood. The patient lies in a special hyperbaric chamber, sometimes called a pressure chamber. The air pressure inside the chamber is about 2.5 times greater than the normal pressure in the atmosphere. This helps the blood carry more oxygen to organs and tissues. The therapy may be used to treat a variety of conditions, such as air or gas embolism (bubbles which block blood flow); bone infections (osteomyelitis); burns; carbon monoxide poisoning; decompression sickness; skin grafts; and wounds that have not healed with other treatments. Hyperbaric therapy was first developed as a treatment for diving disorders involving bubbles of gas in the tissues, such as decompression sickness and gas embolism.