title: Risk factors for high-altitude headache in mountaineers.
abstract: OBJECTIVE
  The aim was to identify most relevant risk factors of high-altitude headache within a broad mountaineering population through a prospective, observational, rater-blinded study.
  
  
  METHODS
  A total of 506 mountaineers were enrolled after their first overnight stay in one of seven alpine huts between 2200-3817 m. Structured interview including information on mountaineering histories, caffeine intake, smoking habits, alcohol consumption, intake of medication, rate of ascent, physical fitness, the level of exertion and the amount of fluids intake at the day of ascent were recorded along with a standardized medical examination.
  
  
  RESULTS
  High-altitude headache occurred in 31% of study participants. Logistic regression analysis revealed a migraine history, low arterial oxygen saturation, high ratings of perceived exertion and fluid intake below 2 l to be independent risk factors for the development of high-altitude headache.
  
  
  CONCLUSIONS
  Given the high prevalence, high-altitude headache is a relevant medical condition and a better understanding of risk factors has important impact and may facilitate patient behaviour and future study design.
authors.affiliation: Department of Sport Science, University of Innsbruck, Innsbruck, Austria. martin.burtscher@uibk.ac.at
authors.forename: Martin
authors.initials: M
authors.lastname: Burtscher
authors.forename: Klemens
authors.initials: K
authors.lastname: Mairer
authors.forename: Maria
authors.initials: M
authors.lastname: Wille
authors.forename: Gregor
authors.initials: G
authors.lastname: Broessner
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology; D000531:Altitude; D000532:Altitude Sickness / Q000453:epidemiology*; D002110:Caffeine / Q000008:administration & dosage; D000697:Central Nervous System Stimulants / Q000008:administration & dosage; D015444:Exercise; D005260:Female; D006261:Headache / Q000453:epidemiology*; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000706:statistics & numerical data*; D010809:Physical Fitness; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine