Headache + two symptoms group (E) of AMS groups was higher than in the other symptoms group (D) (&p = 0.02, D vs E); moreover, IL-1β levels were higher (increased trend) in headache + one symptom group (C) and other symptoms group (D) than in the no-symptom group (A) ($p = 0.013 and @p = 0.03; C vs A and D vs A), suggesting that high-altitude hypoxia-increased plasma levels of pro-inflammatory factors (TNF-α, IL-1β, and IL-6) are associated with AMS. Here, IL6 is linked to Headache.