Headache is one of the most common medical conditions, and migraine is the most common type of primary headache. Some studies have reported that early treatment of migraine includes inhalation of 100% oxygen. The theoretical basis is that the increased oxygen level in the blood acts as an alpha-adrenergic agent that reduces headache pain through vasoconstriction and local metabolic effects. The relief of headache was recorded by visual analogue pain scale and manual palpation, and the results suggested a significant reduction in subjective pain after hyperbaric oxygen treatment, while the control group did not. This study suggests that hyperbaric oxygen therapy can alleviate migraine and that the patient’s subjective evaluation is the best indicator of migraine relief. In addition to this, other studies have reported that hyperbaric oxygen can relieve headache-related swelling and pressure pain. In the past, oxygen inhalation has been used successfully in the treatment of migraine, but more recently, the use of oxygen in the treatment of cluster headache has gained support. While normobaric oxygen (NBO) inhalation (100% oxygen delivered at sea level) therapy is currently the more recognized treatment for cluster headaches, hyperbaric oxygen (HBO) (100% oxygen delivered at higher than normal atmospheric conditions) produces higher levels of oxygen in the blood than NBO, thus producing greater vasoconstriction in the relief of headaches. Migraine is also currently an indication for hyperbaric oxygen. The literature reports that hyperbaric oxygen improves peripheral arterial hypoxia, prevents cerebral vasospasm, and also alleviates the symptoms of vegetative dysfunction that accompany migraine patients. It has also been reported in the literature that the efficacy of hyperbaric oxygen in combination with drug therapy is much better than that of migraine patients who are given only drug therapy alone. In other words, for those migraine patients who are not well controlled by medication alone, hyperbaric oxygen is also a treatment measure.