I've been certified in hyperbaric medicine for 20 years and fill in from time to time at the hospital. It is primarily used for non-healing wounds. Multiplace chambers are also used for decompression sickness. It is not available as a treatment for fibromyalgia as in the above reference as it is high cost, would not be approved, and has risk associated with it (Seizure, barotrauma, Oxygen toxicity)