This book covers the hyperbaric oxygen therapy (HBOT) in current recommended indications, emphasizing the mechanisms involved in the benefits of supplemental oxygen under high pressure. The physiological changes associated with high pressure and hyperoxic conditions are discussed in initial chapters, along with their physical basis governed by the laws of gas followed by the functioning of hyperbaric chambers and the safety precautions needed in operating them. Utilization of HBOT in indications such as wound healing, severe anemia, and burn injuries is thoroughly explained, along with the recommended protocol for HBOT administration. The final chapters present the contraindications of HBOT and its promising effects on aging and regeneration. This book is helpful to HBOT practitioners in understanding its underlying mechanism and major applications.