Many people who visit New Mexico from sea level states commonly report shortness of breath and headaches. Is it altitude sickness?
No. A hotel stay in Santa Fe at 7,260 feet won’t trigger altitude sickness. Once the body detects a decrease in available oxygen, it releases a molecule (2,3 DPG) causing the hemoglobin in the blood to release more oxygen into the tissues. Over time, the kidneys will create more red blood cells (but not before the end of your vacation).
The headache most likely results from dehydration. In New Mexico you can sweat profusely and not notice. Maintain hydration, and when the friendly locals offer more water, drink it.
However, our mountaintops stretch over the 9,000 ft. mark. The ascent to high altitude includes a progressive fall in barometric pressure and a fall in the partial pressure of oxygen. Sustained exertion (like climbing or skiing) above 9,000 feet can trigger altitude sickness.
One of the fist symptoms of altitude sickness includes insomnia and the swelling of the hands and feet (peripheral edema). Altitude related disorders include Acute Mountain Sickness (AMS) and High Altitude Cerebral Edema (HACE). AMS symptoms include loss of appetite, fatigue and weakness. HACE has the same symptoms of AMS with a decrease in coordination and mental confusion.
Climbers at extremely high altitudes can be especially at risk for HAPE, (High Altitude Pulmonary Edema). Early symptoms include cough, nausea, and weakness after 12 to 36 hours at elevation.
Even though the atmospheric proportions remain constant between oxygen and nitrogen at elevation, the overall decrease in oxygen and the decrease in atmospheric pressure can have deadly effects on the lungs.
At 18,000 feet, the body’s access to oxygen decreases by more than one-half. While factors like the Bohr effect and 2,3 DPG will cause hemoglobin to dissociate, making oxygen available to the tissues at rest, the excessive oxygen decreases cannot be compensated by changes in the conformation of hemoglobin and its ability to dissociate from oxygen at elevation.
At this altitude oxygen's partial pressure falls and the mechanisms designed to regulate oxygen and carbon dioxide fail. Breathing requires an inverse relationship between volume and pressure. In order for the lungs to function properly, gas transport must occur when the alveolar pressure and the perfusion of alveolar capillaries remain in the normal range.
To respond to the decrease in blood oxygen, respiration increases. Increased blood CO2 decreases pH and leads to hyperventilation. As a result, vessels construct, decreasing blood flow to the tissues. This in turn limits fluid clearance and contributes to swelling. Fluid leaks from cells and triggers an inflammatory reaction. The climber will then experience breathlessness, gurgling respiration as liquid enters the lungs, and coughs white or pink foamy sputum.
Oooh ... that's bad. At this point, mortality can be as high as 44% where oxygen is not available. The Gammow bag, a portable hyperbaric chamber can treat severe altitude sickness. The bag simulates decent by gradually increasing pressure in the lungs in one hour segments. The other cure: immediate decent.
Feel funny? Go down to the lodge and have a tall glass of water.
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