Can low air pressure cause dizziness and headaches?
Low atmospheric pressure can cause headaches and dizziness, especially for someone not used to being in an environment with low atmospheric pressure. The lower atmospheric pressure means that the air that is being breathed in is less dense and there is less oxygen in a given amount of air. Because lungs cannot expand more than usual to compensate, the result is that there is less oxygen in the lungs during a breath which means less oxygen in the person's bloodstream. The low oxygen levels are what causes the headaches and dizziness.
While even weather changes can bring about these symptoms, they are most often seen at high altitudes. Bodies do adjust for the difference in oxygen levels and adapt to use oxygen more efficiently in these environments. Athletes, for example, are advised to be in the high altitude or low atmospheric pressure environments days in advance before strenuous activity so that their body has time to adjust before being put under stress. Some athletes train in high altitudes so that their body has the added oxygen use efficiency even when doing activities at a higher atmospheric pressure.