In a sense, life is a redox reaction. Most human diseases are closely related to oxygen deficiency, either as a cause or as a consequence of their pathogenesis and development. The world-famous physicist, Edward Taylor, who is known as the father of the hydrogen bomb in the United States, once said with regret: “The cause and development of most human diseases are closely related to oxygen deficiency. Taylor once said with regret: “It is not entirely impossible, that, perhaps sometime in the next decade, professors of medicine will have difficulty in explaining why the treatment with (hyperbaric) oxygen was not widely adopted much earlier. The academician Wang Zhongzhong, who is known as “the giant of the gods” in China, once said emotionally after having done more than 20 hyperbaric oxygen treatments: “The efficacy of hyperbaric oxygen therapy is really amazing, and basic and clinical research should be strengthened!” I have been engaged in the clinical and scientific research of hyperbaric medicine for more than 20 years, and I have a certain experience and understanding of the current situation of the application of oxygen as one of the most natural drugs in the clinic, and I have deep feelings. In this paper, I will only elaborate on the following aspects: I. History of the development of oxygen medicine Oxygen (Oxygen) was developed by the Swedish pharmacist and chemist Scherer and the British chemist Joseph? Priestley discovered in 1773-1774 respectively. Its English name, Oxygen, is derived from the Greek word meaning: acid, and was given by the French chemist Lavoisier, who mistakenly believed that all acids contained this new gas. The Chinese name of oxygen was given by Xu Xian in the Qing Dynasty. He thought that people could not survive without oxygen, so he named it “nourishing gas”, that is, “nourishing quality of gas”, and later, as a kind of gas, the word “nourishing” was replaced by “oxygen” for the sake of unity, and it was written as “oxygen” today. Just as when oxygen was discovered, its discoverer had already profoundly realized how important this gas was to life, human beings have realized that without oxygen there is no life. Some medical pioneers were convinced that the use of oxygen could cure many clinical diseases, and they persevered in many clinical practices. However, the path to the clinical use of oxygen for the treatment of disease is not as smooth as the application of drugs in general. Even after entering the clinic, it seems that it has not received as much attention, investment and in-depth research as many other drugs. The entire medical community seems to have a strange disease that emphasizes drugs rather than oxygen. The reasons for this may be complex and varied. In the first 150 years after the discovery of oxygen, the history of oxygen therapy has been described by the term “Curiosities, Quackeries, and Other Historical Trivia”, although Hozapple administered oxygen to patients with acute pneumonia in York County, Pennsylvania, in June 1885, and various forms of clinical oxygen use that were prevalent in society for a while thereafter. The history of oxygen therapy during this period has been described by the term “Curiosities, Quackeries, and Other Historical Trivia”. This suggests that the pioneers at that time had only curiosity about oxygen therapy and certain historical anecdotes, which were mixed with the deceptive techniques of many quacks who used to swindle money in the name of science. The reason for this may have been the difficulty of obtaining truly pure oxygen for medical use in large quantities and on a consistent basis due to the backwardness of the science and technology involved at the time. However, despite this unsuccessful history of oxygen therapy, most of today’s multiple oxygen-absorbing apparatus and facilities were invented in this era, such as: nasal tube oxygen, face mask oxygen, oxygen tent type oxygen, including oxygen in a hyperbaric chamber… etc. These apparatus and facilities have been repeatedly modified in the later history of oxygen therapy development but are still in use today. It was not until the early 20th century, in 1919, that the British physiologist Haldane wrote in the British Medical Journal that “partial hypoxia does not merely slow down the movement of life, but its further progress may bring about irreversible damage to the structure of the body.” He predicted at the time that oxygen would rapidly enter hospitals as a medical treatment for patients. During World War I, Holden caused a medical sensation when he administered oxygen to chlorine-poisoned soldiers, resulting in a significant reduction in mortality among wounded soldiers. The scientific and rational basis for the modern clinical use of oxygen was laid. 1922 Alvan Barach was the first to systematically use oxygen in the clinical treatment of patients with bacterial pneumonia [7], and he simultaneously modified the oxygen tent invented by his predecessors [7, 8]. He also became interested in the therapeutic effects of oxygen and the mechanism of action of oxygen in relieving locomotor dyspnea. Since then, the application of oxygen has gradually gained importance and oxygen sources have gradually become a necessary and routine medical facility in almost all hospitals. In 1958 Barach invented portable oxygen cylinders suitable for carrying during exercise to facilitate oxygen intake during exercise, Cotes and Gilson meanwhile started oxygen therapy with portable hyperbaric oxygen cylinders for immobilized patients in the U.K. Cotes reported that arterial oxygen saturation could be improved with increased walking time when oxygen was administered during exercise [9]. By 1955 at that time only about 30% of pharmacists in the Monmouthshire area of Wales, England would prescribe oxygen to patients. The main method of oxygen storage and transport at that time was to rely on oxygen cylinders. Obviously this medical practice did not continue or declined in the UK. In the 1960s, with reports of good outcomes in patients with acute carbon monoxide poisoning treated with hyperbaric oxygen, the use of high air pressure to rapidly deliver physical dissolved oxygen to deep oxygen-deficient tissues to treat disease gradually regained interest. The specialty of hyperbaric medicine has subsequently been developed to a certain extent. Barach died in 1976, but he ignited the enthusiasm of many people to seek the value of oxygen therapy and innovate the clinical oxygen delivery method, which promoted the beginning of modern oxygen therapy research and practice. Second, the status of oxygen medicine into the 21st century, science and technology is advancing rapidly, and the development of medicine is no exception. With the birth of Dolly the cloned sheep, the human genome was successfully and rapidly deciphered, so that the entire medical community seems to enter an epoch-making new period. However, despite such advanced science and technology, we can even calculate the exact amount of various nutrients and micronutrients required by each patient who cannot eat every day, and pump the required nutrients into the body through gastric nutrition, intestinal nutrition and, if necessary, intravenous infusion…but we have not dealt with how these nutrients enter the patient’s body to get sufficient But we have not dealt with the problem of how these nutrients enter the patient’s body and how they can be adequately redoxed and ultimately used by the body. Adequate oxygen supply is the basis for the body to restore metabolism, repair itself with various nutrients, and overcome disease. In the current situation, we can easily find that although many aspects of modern clinical medical technology are well developed, only the way and means of medical oxygenation remain almost unchanged for a century. At present, in terms of the oxygen administration apparatus, equipment and methods we use, they are all concepts that have been invented by the ancients for nearly a century. These technologies have undergone some improvements, but no revolutionary advances have been seen. If life is like a balance of redox reactions, the importance of improving oxygen supply has been neglected by us or the development of means has seriously lagged behind other techniques. Clinicians nowadays should say that they are well aware of the importance of improving oxygen deficiency to save various patients, and wall oxygen supply facilities have become a necessity in the infrastructure of hospitals at all levels. Doctors often prescribe oxygen to different patients, but except for some more professional doctors who specify the oxygen administration method and dosage requirements, such as: whether to use nasal tube or mask, high or low flow rate (how many liters per minute) and time, doctors in many departments have a great arbitrariness in giving oxygen to patients, emphasizing medicine but not oxygen, and lacking dynamic monitoring after oxygen administration, observing and judging the oxygen administration There is a lack of awareness and effective means to monitor and evaluate the effect of oxygen administration, and to adjust the oxygen administration mode and dose in time. Furthermore, many front-line doctors today have insufficient understanding of the scope and degree of hypoxia and its impact on the disease process in different pathological periods of patients with different diseases, which is also due to insufficient understanding of the clinical significance of existing clinical testing instruments and indicators such as blood gas and pulse oximetry monitors. For example, a respiratory physician checking the blood gas and oxygen saturation of a patient with a respiratory disease is normal, and it confirms that the patient’s current or treated lung function ensures that the patient is not in a significant hypoxic condition. In contrast, for a patient with traumatic brain injury or cerebrovascular critical illness, the above indicators only reflect the state of the patient’s pulmonary function and the fact that there is no hypoxia in the body circulation, but they are of little significance in judging the cerebral edema, or the circulatory ischemia and hypoxia in the local brain tissue due to local brain tissue swelling. This suggests that the clinical diagnosis and understanding of hypoxia varies greatly in different disciplines of disease, and that the currently commonly used hypoxia tests and monitoring indicators are still limited. It is encouraging to note that the current technological research on invasive and noninvasive tissue partial pressure of oxygen and other local tissue hypoxia assays is in full swing, bringing light to the possibility of providing clinicians with common means of monitoring local tissue hypoxia in the future. In addition, with the increasing understanding of the role of hypoxia in the development of different diseases, there has been a great clinical interest in non-traditional routes and modalities of oxygen administration other than the traditional ones, such as nasal cannula, mask and mechanical ventilation, such as intravenous oxygenation, extracorporeal oxygenation of blood and hyperbaric oxygen therapy. The future of some of these methods is still unknown, but hyperbaric oxygen therapy has shown unlimited vitality in the treatment of clinical multidisciplinary diseases. The so-called hyperbaric oxygen therapy is a kind of physical therapy in which the patient is placed in a closed chamber with high air pressure (usually it is thought that the pressure should be above 1.4 ATA) to inhale pure oxygen intermittently. Under high pressure, oxygen is rapidly dissolved into the bloodstream, and molecular oxygen is supplied to the deeper oxygen-deficient tissues through the flow of the body circulation. This way of delivering oxygen by physical dissolution has the following advantages: 1. Unlike the body that relies on hemoglobin on red blood cells to carry oxygen under normal pressure, its dissolution process in the pulmonary circulation is purely physical and does not require binding to hemoglobin, and this process is not energy consuming; 2. The amount of oxygen that can be dissolved in the blood is as much as 17-21 under normal pressure only at the commonly used 2-3 ATA state of hyperbaric oxygen. It has been confirmed in the literature that the physical dissolved oxygen alone is sufficient to maintain the basic needs of life under 3ATA hyperbaric state; 3. Physical dissolved oxygen in blood is the final form of oxygen used by the body tissues, and sufficient physical dissolved oxygen under hyperbaric state can effectively overcome the vicious cycle mechanism of the body tissues being further aggravated by the lack of oxygen due to edema, narrowing of capillaries under pressure, and inability of red blood cells to pass through. In addition, the molecular oxygen dissolved in the blood fluid component is rapidly supplied to the hypoxic tissues through the narrowed capillaries under pressure, which improves the hypoxic state of deep tissues, thereby rapidly arresting the disease process. Numerous recent reports in the literature have also confirmed from different mechanisms of molecular biology that hyperbaric oxygen therapy has anti-inflammatory, anti-excitatory amino acid, anti-oxidative stress and anti-apoptotic effects, among others. In clinical practice, hyperbaric oxygen has been used for the treatment of more than 130 diseases in various disciplines and has shown good efficacy and promise in various areas such as: noxious gas poisoning, craniocerebral injury, cerebral infarction, refractory wounds, crush injuries, etc. However, the efficacy of hyperbaric oxygen therapy for these diseases lacks reliable evidence due to many reasons, including medical economics, the serious lag in research on dosimetry and toxicology of hyperbaric oxygen therapy for different diseases. This is a serious constraint on the promotion and development of this clinical discipline. Nevertheless, hyperbaric medicine, as an important means to treat diseases or even prevent diseases from the perspective of improving the imbalance of redox reactions in the body, should receive more attention from the medical community, increase investment and in-depth research, and promote the development of clinical oxygen medicine for the benefit of mankind. Oxygen accounts for more than 62% of the composition of the human body. As the main element of the human body, it plays an important role in the reproduction of human life, and in the life of old age, sickness and death. Unfortunately, in such an era of rapid economic development and rapid changes in science and technology, the medical community is far behind other fields in terms of attention and research investment in oxygen medicine. Oxygen medicine needs to be systematized, the knowledge of oxygen medicine among clinicians is relatively weak, the education of oxygen medicine among medical students is lacking, and the basic research of oxygen medicine has not been given due attention, resulting in the lack of theoretical basis for clinical oxygen use, the lack of standardization of operation, the emphasis on drug administration rather than oxygen administration, and the lack of objective basis for judging the efficacy of treatment. We call on the relevant departments and academic institutions to fully recognize the importance of the development of oxygen medicine, increase the support of scientific research investment, and strengthen the propaganda and education of oxygen medicine knowledge, and the education courses of oxygen physiology, biochemistry, pathology, pharmacology and clinical oxygen medicine should be dedicated in the training of medical students. The management of clinical oxygen use should be strengthened, and relevant academic institutions should organize experts to develop feasible clinical oxygen use norms based on existing bases. We believe that the attention and investment in oxygen medicine will be of profound significance in promoting the development of clinical medicine in the 21st century.