Abstract: A method and apparatus for treating altitude related illnesses and/or injuries are provided. Example embodiments provide a hyperbaric therapy device (“HTD”) which includes a chamber constructed substantially from a light weight, high strength, substantially air impermeable material, such as a flexible composite laminate material, such that the chamber can maintain an internal air pressure that is higher than ambient air pressure. In some embodiments, an opening in the chamber of the HTD may be sealed by way of a roll-down, dry bag style closure. The chamber of the HTD may also include multiple inflation valves, to support multiple pump systems for efficient inflation and pressure maintenance. The HTD may also include a storage bag that doubles as a pump for inputting air into the chamber of the HTD.