Acute Altitude Sickness

I apologise for not posting in the last week, I was fortunate to go skiing in the Alps, which was great fun and we had fantastic weather! Whilst I was there a family friend experienced severe headaches, fatigue and repetitive nosebleeds and was later diagnosed with Acute Altitude sickness. I had never heard of this, and what the cause behind it is so I decided to do a post about it. 

Acute altitude sickness occurs at above 2,400m and we were staying in Tignes, which reaches a height of 3030m that makes it a clear location for it to occur. In the mountains there is reduced air pressure and reduced levels of oxygen, these are the cause for mountain sickness because there is increased pressure in the brain caused by swelling or leaking of blood vessels. The sickness is also more common if you’ve had it before or if you climb the mountain quicker or if you do vigorous exercise. It is mild and its symptoms include dizziness, fatigue, nausea, lack of appetite and headaches.

However there are two more severe forms of altitude sickness known as HAPE and HACE, they often occur together and can be very fatal. HAPE stands for high altitude pulmonary edema; the major symptom is feeling breathless when you are at rest, which shouldn’t happen even at high altitudes.  HAPE is when there excess fluid in the lungs, it prevents fresh air getting into the lungs by blocking the air spaces and because the lungs are starved of oxygen blood vessels react by constricting. The blood in these vessels is squeezed so blood pressure goes up which forces fluid of out blood and into air pockets. Other symptoms shown can be coughing up frothy spit and a high temperature.

HACE stands for high altitude cerebral edema and has symptoms very different to HAPE these are dizziness, clumsiness and stumbling, these all occur due to fluid in the brain. This fluid is due to excess blood flowing into the brain, however this can damage blood vessels, which can lead to leaking. It is also believed that chemicals are released when oxygen levels are low which can damage blood vessel membranes.

Both HACE and HAPE are life threatening and so a decent down the mountain would be essential and oxygen bags can extend life time in severe cases. 

Sources:

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001190/  

http://www.altitude.org/altitude_sickness.php