Mountains are a wonderful thing. In fact, they are the
preferred geological formation of the Sketchy Science team. That is why we have
spent the past several weeks on and recovering from a research expedition to
some of the highest peaks North America has to offer: the 14,000 foot peaks of
Colorado’s Rocky Mountains. While peaks in Alaska, B.C., and the Yukon attain
higher elevations, none can rival Colorado for sheer accessibility.
Accessibility is what you need if you want to study and
report on altitude sickness. With this in mind, our writer (me) and illustrator
loaded up our respective vehicles and drove, with our romantic partners and two
canine companions, from our elevations of residence (0 feet/m and 1,000
feet/300 m respectively) to the highest city in the continental United States:
Leadville, CO (10,200 feet, 3,108 m).
Altitude impacts the human (and canine) body in a number of
important ways, but they all stem from the fact that the air at altitude is
less dense. At low elevations air is compressed by the weight of all the air
above it. As you move towards the stratosphere, the column of air you exist in
becomes shorter (there is less air above you), and so the weight is lessened and
particles have more freedom to stretch out from one another. It isn’t that
there is less oxygen in the air (the rate is a pretty constant
21% regardless of altitude), but in the mountains there is more space
between oxygen molecules.
Aside from the relatively straightforward problem of your
body not being able to get enough oxygen, the air at altitude is also drier.
This causes your tissues to lose water rapidly to the air. Your body responds
by constricting blood vessels and holding on to water and sodium in areas like
the kidneys. The end result is higher blood pressure, a more rapid heartbeat,
and an imbalance of moisture and salts.
At altitudes as low as 5,000 feet/1,524 m, this can lead to disturbed
sleep as your body struggles to balance oxygen and carbon dioxide by
interrupting your breathing during the night. The upshot is you are unrested as
you head out exploring the mountains and you make your other symptoms (if you
have any) worse. During the day, your body compensates for thin air by
breathing more rapidly, leading to headaches, nausea, and dehydration.
At extreme altitudes (above 18,000 feet/5,486 m), the
effects on your body can be life-threatening. The two most dangerous conditions
are High
Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE).
Both are the result of fluid leaking from your constricted blood vessels and
collecting in your tissues. With HAPE, the fluid gathers in your lungs. You
struggle to breath and can effectively drown without ever touching water.
Unbelievably, HACE is worse as the fluid gathers in your brain. The increased
pressure in your skull leads to confusion, lack of coordination, and sometimes
coma and death.
Curiously, altitude doesn’t hit everyone the same way and it
is tough to predict who will struggle and who will thrive where the air is
thin. Marathon runners are no better off than habitual couch potatoes. If the
symptoms are mild (headache, nausea, fatigue), then they generally fade with
more time spent at altitude – this is called acclimatization. With rest and
plenty of water you will start to feel better in as little as 12 hours. The US
Army reports that the respiratory element of acclimatization is 70-80%
complete within 7 to 10 days. Between 14 and 30 days you are 80 to 90%
acclimatized. Total acclimatization can take months or years, though.
If, like us, you are not in immediate danger and have more
ambition than common sense, you can find help from over the counter drugs like ibuprofen
or by eating foods that are high in carbohydrates like pasta and bread. You
can also prevent altitude sickness by spending a night at lower elevation
before going higher and by ascending in stages with rest days to let your body
get used to the new environment more gradually.
In the end, the hardest part about exploring the
high-country is balancing respect for your health and the power of nature
(storms, avalanches, and stuff) with the urge to be a hero. Pain is temporary
and glory is forever, but death is even more
forever. So be safe and be responsible, but enjoy the mountains and the freedom
they bring.
