Table 1 Comparison of AMS and no-AMS (total n = 74) volunteers at an altitude of 3860 m

AMS

33/74 (44.6 %)

16/74 (21.6 %)

11/74 (14.9 %)

 Headache

33/33 (100 %)

16/16 (100 %)

11/11 (100 %)

No-AMS

41/74 (55.4 %)

58/74 (78.4 %)

63/74 (85.1 %)

 Headache only

8/41 (19.5 %)

7/58 (12.0 %)

6/63 (14.6 %)

 Headache + one symptom

9/41 (21.9 %)

9/58 (15.5 %)

3/63 (4.8 %)

Others (no-headache)

12/41 (29.2 %)

15/58 (25.9 %)

14/63 (22.2 %)

No symptom

12/41 (29.2 %)

27/58 (46.6 %)

40/63 (63.5 %)