Testing with the CPAP machine revealed that it was triggering altitude sickness symptoms after waking, specifically ‘Descent Fatigue’ during the daytime.

At the age of 50, my Descent Fatigue is now so severe that I no longer venture to high altitudes unless I have to.

Most high altitude workers experienced fatigue after descending to sea level at the end of the work day. No one appeared to know what it was and I now call it ‘Descent Fatigue’.

My suspicion about what causes Descent Fatigue in high altitude workers is related to reperfusion of thickened hypoxic blood.

The most painful experience that I had in high altitude astronomy was ear barotrauma on descent from the observatory. After experiencing this horrible condition a few times, I got wise and would always carry nasal decongestant medication with me to help prevent it. I saw many people experience the condition so severe that we had to stop descending in the car and sit at the side of the road until it subsided in the unfortunate high altitude worker.

14,000 feet (4,267 meters) and above: Most people who ascend above 14,000 feet (4,267 meters) develop some form of altitude disease. Descent is the recommended treatment.