The Lake Louis Clinical Score (LLCS) was used
to evaluate AMS symptoms at their worst occurring
within the first 48 hours in Cusco. To calculate the
LLCS, symptoms associated with AMS, like headache,
nausea and vomiting, dizziness, fatigue, or sleeping
disturbances were graded from 0 to 3 points according
to severity. The points were summed and a total score
of 3 or more was diagnostic of AMS if headache was one
of the symptoms. Similarly, severe AMS was defined as
a score of 6 or more. Subjects were questioned about
prior illnesses including high altitude-related illnesses
and chronic medical conditions like obesity, chronic
obstructive pulmonary disease, congestive heart failure,
sleep apnea syndrome, and cardiac arrhythmias.