Hiking at Altitude vs Altitude Sickness

I've never been at high altitude and didn't know much about it. I'm a bit anxious about what it will be like so I've been doing some research. What I've learned is that it is normal to be out of breath when exerting yourself at altitude and that this is different than having Altitude Sickness.

Credit: The Conversation

I found this graphic helpful for understanding what happens to oxygen levels at altitude. With the 'thinner' air, the body takes in less oxygen with each breath.

The most immediate and obvious response is that we start to breathe more. There are other adaptations that the body starts to undergo and while I don't understand all the chemistry and biology, one side effect of these changes is increased urination.

Exerting yourself, such as hiking up a mountain, under these conditions would mean that you would need to breathe even more heavily than usual. Plus, due to the reduced amount of oxygen going to your muscles, physical performance is never as good at altitude as it is at lower elevations.

The process of adapting to the new conditions is referred to as acclimatization.  Opinions seem to differ on how long it takes the body to acclimatize: some say 1-2 days, others suggest 5-7. Apparently, it would take around a month to acclimatize fully.

My take-aways:

• Regardless of the level of fitness I achieve before I go, I can expect to be breathing heavily on the trail, along with everyone else (except maybe our guides and porters - it is fascinating to see how the human body adapts differently in different high-altitude peoples!).
• I may feel that my muscles aren't performing to the same degree as they do here. 
• I should make sure I'm carrying lots of toilet paper! 

Altitude Sickness, sometimes called Acute Mountain Sickness, is something different. Headache, nausea, lethargy, dizziness, loss of appetite, and sleep disturbances are all symptoms that can develop when the body is not adapting to the altitude as well as it might. Why some people get altitude sickness and others don't seems to be a mystery. It is not related to fitness level, age, gender, or health conditions. Some people are just more prone to it than others. The best predictor is what happened that last time you were at altitude! So I have nothing to go on :-)

The best way to prevent altitude sickness is to ascend slowly, giving your body time to adjust. And because of the water loss due to increased breathing and urination, it is important to drink more than you normally would to avoid dehydration.

It seems symptoms of altitude sickness are usually mild and can be dealt with easily by giving the body time to adapt or by returning to lower altitudes. Some people swear by natural remedies, such as chewing cocoa leaves or drinking tea made from them, however there seems to be little empirical research to support these claims.  There is one prescription medication, Diamox, that has proven to help with the acclimatization process.

My take-aways:

• Although the trip already has 3 days to acclimatize before we start hiking, I am going to add 1-2 days to give my body a little extra support. 
• I don't drink enough water in my normal life, so I am going to need to be very intentional about drinking enough liquid on this trip. 
• Normally, I avoid taking medications unless absolutely necessary. I'd rather be safe than sorry on this one, so I am going to get a prescription for Diamox, and will take it if I find I'm having issues after the first couple of days. 

There are two other, more critical conditions that can occur at altitude, pulmonary edema (HAPE) and high-altitude cerebral edema (HACE), but these are rare and I don't think I will need to worry about them.