Diamox (acetazolamide or AZ) has been a favorite topic here on WZ years.
It works great at altitude for some, partially for others, and little or none for others. . And some have side effects or become allergic to it. Plenty of people have climbed to extreme altitude without it.
Respiratory control "sensors" are disturbed upon ascent. By stimulating involuntary breathing (while asleep) AZ can decrease periodic breathing that mainly occurs at night at altitude. Bob and Frank have described the symptoms and good response for them. Some people have periodic breathing and do not wake up. Others alternate stopped breathing and gasping. Folks vary. Daytime is far less of a problem because breathing is voluntarily increased and controlled. AZ and acclimatization can both both reduce periodic breathing, making it less clinically apparent or seemingly absent to the user, but not totally gone. That led to the "rule change" I mentioned.
If anyone wants more information on this, the International Hypoxia Symposium is held in Lake Louise, Alberta, hence the name of the altitude illness scoring system. Periodic breathing was NOT removed from being a fact at higher altitudes. It IS a fact. It was only removed from the scoring system for AMS.
