Hyperbaric oxygen therapy (HBOT) puts a person in a completely closed pressure chamber, which increases the pressure and oxygen concentration to nearly five times that in normal ambient air. The principle of hyperbaric oxygen therapy is to increase the pressure and oxygen concentration in the blood, aiming to improve blood circulation, promote body metabolism, and enhance immunity.

HBOT has been used widely by the U.S. Navy to treat decompression sickness (DCS) in soldiers as early as 1940. DCS is a fatal condition due the drastic change in the air pressure which leads to the formation of air bubbles form in the blood. HBOT technology continues to develop in medical care. In 2018, Pamela Youde Nethersole Eastern Hospital also began to provide HBOT, mainly to help relieve severe diseases and accelerate tissue repair, such as stroke, flesh-eating disease, ulcers after radiation therapy, etc.

With the popularity of HBOT, this treatment is no longer limited to severe patients. In recent years, many athletes, such as US Olympic swimming gold medalist Phoebes and NBA basketball player Le Bon James, have used HBOT to repair post-exercise strain and improve overall performance. Scientists in Israel studied the effect of HBOT on mice and found that the mice who had been treated with HBOT had a significant increase in basic cognitive ability and memory. They have since found that the same principle can be applied to patients with high stress or emotional distress.

HBOT can effectively improve insomnia and emotional management, a finding that brings an additional option for chronically stressed urbanites. Hollywood superstar Keanu Reeves also uses hyperbaric oxygen to relieve insomnia and improve his mental state and work performance.