Objectives The purpose of this study was to compare two scoring systems used for diagnosis of acute mountain sickness (AMS): Lake Louise Scoring (AMS-LLS) and Chinese Scoring System (AMS-CSS).

Methods 339 healthy young adult volunteers, resided at sea level (mean ± SD: age 24.59 ± 3.27 years; height 173.93 ± 5.18 cm; weight 68.21 ± 7.79 kg), ascended to 3200 m by train and bus, a total journey time of 48 hours, all the persons were ascend as same way, and were divided into three groups. Group 1 (n = 88), group 2 (n = 91) and group 3 (n = 160) were assessed after one, two and three nights, respectively, at altitude.

Results The overall incidence of AMS was 17.11% (n = 58) and 29.79% (n = 101) according to AMS-LLS and AMS-CSS, respectively. Two participants (0.59%) experienced high altitude pulmonary edema. Both scoring systems showed the highest incidence of AMS after the second night at high altitude. There was a good correlation between AMS-CSS and AMS-LLS scores (Pearson = 0.820, P < 0.001). AMS-CSS identified all AMS subjects diagnosed by AMS-LLS, plus an additional 43 missed by AMS-LLS. The dominant symptoms were reduced exercise tolerance (61.7%), fatigue (49.05%), dizziness (28.9%), chest distress (28.3%) and headache (27.4%). Compared with AMS-LLS, the sensitivity, specificity, and positive and negative predictive values of AMS-CSS were 100%, 84.7%, 57.43% and 100%, respectively. There was no relationship between oxygen saturation (SpO₂) levels and AMS scores at 3200 m.

Conclusions AMS-CSS is similar, but a little different details, with AMS-LLS. AMS positive diagnosis outnumbers the LLS standard, but there might be a false positive. Headache was not the dominant symptom at 3200 m high altitude in this study, and SpO2 levels did not correlate with AMS scores.