Mankind lives, works, and plays within an extensive range of high- and low-pressure environments. It is important to understand how altitude affects atmospheric pressure and subsequent alveolar oxygen availability. In addition to pressure-related changes, there are multiple environmental stresses that occur during high-altitude exposures that amplify potential dangers. The most serious complications of altitude exposure are associated with a syndrome known as acute mountain sickness (AMS). Typical symptoms include headache, nausea, anorexia, insomnia, and, occasionally, vomiting. A variety of medications may impact the course of these conditions. The sulfa-based, carbonic anhydrase inhibitor diuretic, acetazolamide, induces metabolic acidosis, stimulating ventilation and thereby mimicking the natural respiratory response to altitude, which may assist in hastening acclimatization. Hyperbaric chambers, commonly used for treatment of diving injuries, carbon monoxide poisonings, or wound care, are examples of the therapeutic benefits of elevated pressures. Capnometers measure either partial pressures or percent volumes of gases.