Autism (autism) is a developmental disorder caused by congenital impairment of brain function or metabolic abnormalities and can usually be detected before the age of two and a half. From an early age, individuals with autism exhibit characteristics that are different from those of the average child, such as difficulty understanding and expressing language, difficulty establishing emotions with those around them, abnormal responses to a variety of sensory stimuli, and fixed play and behaviors that are unchanging and difficult to change. The characteristics of autism may vary with age, IQ and severity of autism, such as impairment in interpersonal relationships; impairment in language function; and homogeneity of behavior. The incidence of the disease is generally considered to be about: 5-10/10,000, with a ratio of male to female patients of about 5 to 1. There are no detailed studies on the disease in China, and the incidence is conservatively estimated at 1/1000, with about 500-1 million people. Its causes are not medically conclusive at present, and it is likely that multiple factors cause damage to different parts of the brain. As for the factors that may cause autism, they may be related to the following aspects: genetic factors, viral infections during pregnancy, metabolic diseases, brain damage, etc. The main treatments for autism are biological therapy (detoxification), behavioral intervention therapy (training), Chinese herbal medicine (massage, acupuncture), etc. Hyperbaric oxygen is a treatment method that has attracted attention only in recent years. Among them, biological therapy has been studied earlier in foreign countries, mainly because it is believed that the biochemical function of children with autism has malfunctioned, resulting in the accumulation of heavy metals in the body, which leads to hyperactivity, inattentiveness and other behavioral problems, and fasting and detoxification are the main elements of biological therapy. Behavioral intervention therapy mainly refers to various functional training, such as: sensory integration training, language training, visual training, auditory training, etc. Because autistic children have a disorder in the processing of various information, training interventions are used to re-establish new reflexes. In recent years, hyperbaric oxygen has been found to have a more pronounced therapeutic effect on the disorder, and the best treatment period for autism is from 2 to 7 years of age. If the child undergoes systematic and scientific interventions during this period, 20%-30% of them can take care of themselves, and some of them may have a skill and return to the society successfully. The therapeutic mechanism of hyperbaric oxygen for autism Since the pathogenesis of autism itself is not very clear, it is difficult to give the exact therapeutic mechanism of hyperbaric oxygen therapy, but its effect may be related to the following aspects: 1. Hyperbaric oxygen can rapidly improve the lack of oxygen in the body and promote the growth and development of brain tissue. Children’s brain development is not perfect before 7-8 years old, hyperbaric oxygen can promote the development of nerve cells and repair of damaged tissues, thus promoting the recovery of brain function. 2. Hyperbaric oxygen can inhibit the growth and reproduction of anaerobic bacteria. The bacteria in the intestinal tract are partly anaerobic bacteria. Some children with autism have dysbiosis of intestinal flora, dysfunction, dense stool, etc. Long-term dense stool is not conducive to the excretion of toxins, but increases the absorption of toxins, hyperbaric oxygen can promote intestinal peristalsis, which has a certain therapeutic effect on dysbiosis of intestinal flora. 3, hyperbaric oxygen has significant therapeutic effect on viral infections. For example, viral encephalitis, autism causes part of the view that it is related to viral infection, hyperbaric oxygen has a certain inhibitory effect on virus reproduction, can relieve the cell edema caused by infection, and quickly restore the function of cells. 4. Hyperbaric oxygen can inhibit allergic reactions. It is mainly done through the action on mast cells. Many autistic children have food allergy problems, and this kind of allergy is difficult to choose to treat with anti-allergic drugs. 5. Hyperbaric oxygen can promote the metabolism of the body and enhance immunity. If autism is related to excessive heavy metals in the body, compared with normal children, the diet structure should not be very different, and its intake should be the same, the problem lies in the metabolic disorder of heavy metals, the metabolism of substances requires the joint participation of enzymes and oxygen, and even the formation of enzymes also depends on the presence of oxygen, so hyperbaric oxygen can accelerate the metabolism of substances and promote the excretion of heavy metals.