The Chamber

• Hyperbaric Oxygen Therapy (HBOT) is the medical procedure of breathing 100 percent oxygen under increased atmospheric pressure. The patient enters a specialized hyperbaric chamber that regulates the flow of oxygen and controls air pressure. The treatment allows blood to carry more oxygen to body tissues by increasing the level of oxygen within blood plasma.
  
  Hyperbaric oxygen therapy involves three distinct phases; compression, treatment and decompression. In small (monoplace) chambers the patient lies flat while the area is filled with 100 percent oxygen. In large (multiplace) chambers individuals sit upright while an oxygen hood or a valve mask delivers a specific ratio of oxygen through each device. These larger chambers often have space for 12 or more people, so it's likely that several patients will share the space during hyperbaric procedures.
  
  

Compression

• This is the time period during which pressure is increased around the body. " You will feel a fullness of the ears, similar to that felt while skin diving, descending in an airplane, or driving down a high mountain," according to the Hyperbaric Medical Center at the University of California at San Diego. "The hyperbaric chamber operator will adjust the rate of pressure change according to your ability to relieve this fullness in your ears. The operator and the staff member accompanying you in the chamber will teach you methods of easing the pressure in the ears. This phase usually lasts about five minutes."
  
  

Treatment

• When the pressure prescribed by a physician has been reached, patients in most chambers may read, watch television or listen to music. Depending upon the specific medical condition, treatment time will vary between one and two hours. Depending upon the facility and the illness, some patients may breathe 100 percent oxygen for a set period of time, take a short break with normal oxygen intake, then resume treatment with 100 percent oxygen.
  
  

Decompression

• The operator will reduce the atmospheric pressure within the chamber, and patients may notice their ears adjusting automatically, similar to when one descends from a high altitude. The total time for this stage varies from five to 10 minutes for most hyperbaric procedures.
  
  

Restrictions

• Due to the high concentration of flammable oxygen inside the chamber, hairspray, make-up, perfume, vaseline and other products made from petroleum are not allowed. Patients are advised to avoid using skin-care products like lotions, which also are petroleum-based, prior to entering the chamber. Any item which may produce a spark is banned and individuals will be given special, non-flammable hospital scrubs to wear during the therapy.
  
  

Side Effects

• The Duke University Center for Hyperbaric Medicine says that some patients will notice their vision has become nearsighted. "This is usually only temporary and should disappear three to four months after the treatments stop," says Duke physicians. "Other side effects are extremely rare." However, smokers are advised to avoid lighting up between treatments as this reduces the efficiency of the treatment.