Cerebral infarction (called stroke in Chinese medicine) refers to ischemic necrosis of restricted brain tissue caused by occlusion of blood vessels due to blood supply disorders in the brain, which are commonly seen clinically as cerebral thrombosis and cerebral embolism. The most common cause of cerebral thrombosis is atherosclerosis, and cerebral embolism refers to the embolization of foreign emboli in cerebral arteries via blood circulation, resulting in brain dysfunction in the corresponding blood supply area. Cerebral infarction can cause dizziness, hemiparesis, aphasia, sensory impairment and other symptoms of impaired or lost brain function in the corresponding infarct area, and the root cause of these symptoms is the ischemia and hypoxia of brain tissue in the infarct area. Hyperbaric oxygen therapy is a non-invasive clinical treatment in which patients inhale pure oxygen in a high-pressure environment (atmospheric pressure is one atmosphere, and more than two atmospheres is high pressure), and it has the following therapeutic effects 1, hyperbaric oxygen can rapidly increase the partial pressure of blood oxygen and improve the diffusion amount and diffusion distance of oxygen, increase the oxygen content of brain tissue, improve the blood supply to the tissue parts of cerebral infarction lesions, and improve the hypoxic state of brain cells. 2.Hyperbaric oxygen can reduce cerebral edema and lower intracranial pressure, thus blocking the vicious cycle of hypoxia-edema. 3.Hyperbaric oxygen can promote capillary neovascularization and the formation of collateral circulation, so that the oxygen-deprived neural tissue can regain oxygen supply. 4.Hyperbaric oxygen can reduce blood viscosity, inhibit platelet aggregation, enhance the activity of fibrinase, promote the dissolution and absorption of thrombus, and improve microcirculation. 5.Hyperbaric oxygen can protect the mitochondrial function, increase the ATP content of brain cells, improve the energy metabolism of brain tissue, restore the normal metabolism of brain cells, and promote the recovery and regeneration of nerve cells. 6.Hyperbaric oxygen can reduce cerebral ischemia-reperfusion injury, restore the function of “ischemic penumbra”, inhibit the release of excitatory amino acids, regulate the secretion of nitric oxide, and reduce the damage of free radicals. Understanding the above therapeutic effects of hyperbaric oxygen, it is easy to see the important role of hyperbaric oxygen in the treatment of cerebral infarction. A large number of clinical studies have also confirmed that hyperbaric oxygen therapy can reduce the area of infarct foci, restore neurological function and reduce the sequelae of infarction. But when is hyperbaric oxygen therapy good for cerebral infarction? Clinical studies have found that if there are no contraindications to hyperbaric oxygen therapy for cerebral infarction, the earlier the treatment, the better. Early hyperbaric oxygen therapy can improve cerebral hypoxia as soon as possible, save brain cells that have not yet died, enable the formation of new blood vessels as soon as possible, establish collateral circulation as soon as possible, and interrupt the vicious cycle of hypoxia-brain edema-brain cell death. The length of treatment should be determined according to the patient’s condition, generally a course of treatment is 10 times, once a day, each time takes two hours, the total treatment course should be decided by the doctor of the hyperbaric oxygen department according to the needs of the condition, in the hyperbaric oxygen treatment at the same time should be carried out at the same time drug therapy. The best treatment method is to combine the two treatments.