Planning on a big expedition in the high alpine or thinking about bagging that peak on your
bucket list? Before you go, have you ever heard of HAPE, or high altitude pulmonary
edema? HAPE is a more severe form of AMS or Acute Mountain Sickness. The cause of acute
mountain sickness is still unknown, but some medical sources think it might be related to genetics.
Therefore, physical ability (or lack thereof) does not make people predisposed. HAPE occurs
when fluid begins to build up in alveoli (small air sacs found in lungs).
Where does AMS & HAPE Occur? AMS can start to occur between 5,000ft & 11,500ft or high
alpine environments. Where you should start to be concerned is above 11,500ft up to 18,000ft
(very high altitude) where oxygen saturation begins to decrease below 90%. Extreme elevations
(18,000ft ยญ 26,000ft) is considered the hypoxic level. Above 26,000ft is considered the โDeath Zoneโ
or altitudes unable to support life.
How to correctly identify symptoms of AMS and advancing stages of HAPE; while AMS is not
exactly life threatening and symptoms can be less severe, they can rapidly accelerate into life
threatening signs of HAPE. Signs of AMS can range from headache, fatigue, lack of appetite, and
nausea. Advancing signs of HAPE are a mild fever, breathlessness at rest, rapid heart rate, (more
advanced) gurgling or cracking noises while breathing, and (most advanced) exhibiting pink flem.
How to treat AMS and HAPE; for acute symptoms of AMS the best treatment is rest, fluids,
and acclimatization. If available, acetazolamide can be helpful in speeding up oneโs respiration
rate which can alleviate AMS. People exhibiting signs of HACE should be given oxygen and
should descend in elevation trying best not to use too much energy.
P.S. Watch out for HAPEโs cousin, HACE; High Altitude Cerebral Edema. While HAPE gets
all the headlines, there lurks an equal killer lying in wait. Rapid ascent can also lead to
increased blood flow to the brain resulting in swelling and death. Symptoms range from
confusion to ataxia (loss of control of body movement). The best treatment (like HAPE) is
descending in elevation & oxygen.