This question exemplifies the oxygen paradox. It has both beneficial and detrimental effects on the body. Low oxygen levels in the tissues of the body allow disease to develop and grow. High levels, such as might result from hyperbaric chamber sessions, may increase the oxygentiative damage caused by oxygen and its metabolism by our cells. You really need to consider the possible benfits of the hyperbartic oxygen, and weigh them against possible problems caused by increased levels of free radicals. Most doctors in this field think that free radical quenching vitamins such as C (for free radicals in watery portions of the body and its cells) and E (for frd within lipid areas) plus their co-factors can dramatically lessen the chance of any significant harm from excess free radicals in hyperbaric oxygen therapy.