Mountain Sicknesses

Chronic Mountain Sickness was mentioned a number of times as the source of a patients problems. I was very curious about it, so I asked a few of the doctors for more details.

Acute Mountain Sickness, more commonly known as altitude sickness, is what happens to people from sea level when the move to a high altitude. They lose some appetite, have to sleep more, and can sometimes faint from lack of oxygen. Even athletes will feel short of breath if they climb a hill quickly. All this is because there's less oxygen in the air, so the body has to work a lot harder to maintain itself even when resting.

Chronic Mountain Sickness is what happens to people who live their whole lives at high altitudes. My original understanding of the local people here is that they basically had a superpower. Their lungs are bigger and their blood has a high red blood cell count.* If they were to move to sea level, they would be able to run farther and faster without much trouble. It's an advantage I'm hoping to to capitalize on as a runner when I go back to Boston after 2 years in the mountains.

But it turns out it isn't as straightforward as I thought things were. Even though these people are adapted to living with less oxygen, it isn't enough. Here's what wikipedia's got to say on Chronic Mountain Sickness:

CMS is characterised by polycythemia (with subsequent increased hematocrit) and hypoxemia which both improve on descent from altitude. CMS is believed to arise because of an excessive production of red blood cells, which increases the oxygen carrying capacity of the blood ^[2] but may cause increased blood viscosity and uneven blood flow through the lungs (V/Q mismatch). However, CMS is also considered an adaptation of pulmonary and heart disease to life under chronic hypoxia at altitude.

Human beings didn't evolve at 3000 feet, so even with useful adaptations, the bodies of people living at high altitudes are working harder every moment to stay alive than the bodies of people at sea level. Their bodies aren't getting enough oxygen, even with their higher red blood cell count. One army medic compared it to having more soldiers on the field, but having each soldier be less effective (soldiers = red blood cells). The effects are similar to that of smoking (except they don't have black lungs and an increased lung cancer risk). Breathing gets more difficult as time goes on. It can lead to all sorts of secondary problems as different organs fail to function at their full potential.

An interesting aspect of Chronic Mountain Sickness is that it isn't just an altitude based problem. It's also a geography based problem. Again, wikipedia: 

Although CMS generally affects people native to altitudes higher than 3000m, it does not affect populations around the world equally. A recent study by Sahota and Panwar (2013)^[2] reviewed CMS prevalence rates around the world and found the highest rates were found in Andean countries of South America

It doesn't seem to be clear why it affects residents of the Andes (around 16%) more than residents of the Himalayas (around 5%). I guess this is what JVC means when they say "sit with the questions."

Chronic Mountain Sickness has basically one good treatment: moving to a lower altitude. Unfortunately for most people here moving to a lower altitude just isn't a viable option. Their families are here, their lives are here, not to mention most people don't have the savings to pull off a move, especially late in their lives. 

The takeaway isn't that everyone who lives at altitude is doomed to a shorter life. The takeaway is that this is a harsh place to live.

*red blood cells are what carry oxygen around to all the cells of the body.