Back To Search Results

Acute Mountain Sickness Score

Editor: Philipp J. Underwood Updated: 3/27/2023 8:41:40 PM


Acute mountain sickness (AMS) is a syndrome that arises in non-acclimatized individuals who ascend to high altitudes. It is a form of acute altitude illness that occurs due to decreased atmospheric partial pressure of oxygen as the altitude increases, inducing hypoxia. This condition typically occurs at an altitude of >2500 meters; however, it can occur at lower elevations in high-risk individuals.[1][2]

Clinical Significance

Register For Free And Read The Full Article
Get the answers you need instantly with the StatPearls Clinical Decision Support tool. StatPearls spent the last decade developing the largest and most updated Point-of Care resource ever developed. Earn CME/CE by searching and reading articles.
  • Dropdown arrow Search engine and full access to all medical articles
  • Dropdown arrow 10 free questions in your specialty
  • Dropdown arrow Free CME/CE Activities
  • Dropdown arrow Free daily question in your email
  • Dropdown arrow Save favorite articles to your dashboard
  • Dropdown arrow Emails offering discounts

Learn more about a Subscription to StatPearls Point-of-Care

Clinical Significance

The syndrome can present as a mild self-limiting disease with the presentation of non-specific symptoms such as dizziness, headaches, sleep disturbance, nausea, and vomiting. However, it may also progress to life-threatening complications such as high-altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE).[3][4][5] Hence, early identification of individuals with the presentation of AMS symptoms can help prevent severe complications. The Lake Louise Questionnaire (LLQ) and the Acute Mountain Sickness-Cerebral score (AMS-C) are two assessment tools for identifying acute mountain sickness.

 The AMS-C score derives from the Environmental Symptom Questionnaire (ESQ), which was formulated in 1979 to assess symptoms induced upon exposure to extreme environmental conditions. ESQ-III, the third and final revision, consisted of 67 questions, of which 11 are categorized to AMS-C. The questions are scored on a scale of 0 to 5, with 0 reported as “not at all” and 5 reported as “extreme.” Each response score is then multiplied by the factorial weight of its symptom and a score of 0.70 or greater classified as AMS-C. Due to ESQ-II being an intricate assessment tool, it is less frequently used.[6][7]

The Lake Louise Questionnaire was introduced in 1991 and was last modified in 2018.  It is now the most commonly used scoring system used to assess AMS. It defines AMS as the presence of headaches in addition to three other symptoms, including gastrointestinal symptoms, fatigue/weakness, and dizziness/lightheadedness. Each symptom is appointed a point on a scale from 0 to 3, with 0 being no effect and 3 being severe. A total score of 3 or greater, with the presence of headaches, in a setting of rapid ascent to high altitude, is diagnosed as acute mountain sickness. The Lake Louise Questionnaire, although an effective assessment tool, has its limitation. It is a scoring system to standardize and diagnose AMS for use by investigators or research purposes, and it is not meant for clinical practice.[1]

Nursing, Allied Health, and Interprofessional Team Interventions

Currently, no biomedical tests are available to diagnose acute mountain sickness; therefore, the disease is diagnosed based on the presentation of clinical features. The scoring scales serve to identify and assess the presence and intensity of clinical features in an AMS individual.[8] Individuals with a mild presentation of AMS receive treatment with supportive care with rest, hydration, and analgesic medications. Treatment for more severe cases of AMS includes oxygen and drugs such as acetazolamide or dexamethasone and descent in altitude.[8][9][10]



Roach RC, Hackett PH, Oelz O, Bärtsch P, Luks AM, MacInnis MJ, Baillie JK, Lake Louise AMS Score Consensus Committee. The 2018 Lake Louise Acute Mountain Sickness Score. High altitude medicine & biology. 2018 Mar:19(1):4-6. doi: 10.1089/ham.2017.0164. Epub 2018 Mar 13     [PubMed PMID: 29583031]


Berger MM, Sareban M, Bärtsch P. Acute mountain sickness: Do different time courses point to different pathophysiological mechanisms? Journal of applied physiology (Bethesda, Md. : 1985). 2020 Apr 1:128(4):952-959. doi: 10.1152/japplphysiol.00305.2019. Epub 2019 Dec 12     [PubMed PMID: 31829805]


Prince TS, Thurman J, Huebner K. Acute Mountain Sickness. StatPearls. 2023 Jan:():     [PubMed PMID: 28613467]


Gallagher SA, Hackett PH. High-altitude illness. Emergency medicine clinics of North America. 2004 May:22(2):329-55, viii     [PubMed PMID: 15163571]


Fan N, Liu C, Ren M. Effect of different high altitudes on vascular endothelial function in healthy people. Medicine. 2020 Mar:99(11):e19292. doi: 10.1097/MD.0000000000019292. Epub     [PubMed PMID: 32176054]


Bartsch P, Bailey DM, Berger MM, Knauth M, Baumgartner RW. Acute mountain sickness: controversies and advances. High altitude medicine & biology. 2004 Summer:5(2):110-24     [PubMed PMID: 15265333]

Level 3 (low-level) evidence


Dellasanta P, Gaillard S, Loutan L, Kayser B. Comparing questionnaires for the assessment of acute mountain sickness. High altitude medicine & biology. 2007 Fall:8(3):184-91     [PubMed PMID: 17824818]


Meier D, Collet TH, Locatelli I, Cornuz J, Kayser B, Simel DL, Sartori C. Does This Patient Have Acute Mountain Sickness?: The Rational Clinical Examination Systematic Review. JAMA. 2017 Nov 14:318(18):1810-1819. doi: 10.1001/jama.2017.16192. Epub     [PubMed PMID: 29136449]

Level 1 (high-level) evidence


Simancas-Racines D, Arevalo-Rodriguez I, Osorio D, Franco JV, Xu Y, Hidalgo R. Interventions for treating acute high altitude illness. The Cochrane database of systematic reviews. 2018 Jun 30:6(6):CD009567. doi: 10.1002/14651858.CD009567.pub2. Epub 2018 Jun 30     [PubMed PMID: 29959871]

Level 1 (high-level) evidence


Zhu X, Liu Y, Li N, He Q. Inhaled budesonide for the prevention of acute mountain sickness: A meta-analysis of randomized controlled trials. The American journal of emergency medicine. 2020 Aug:38(8):1627-1634. doi: 10.1016/j.ajem.2019.158461. Epub 2019 Oct 23     [PubMed PMID: 31706656]

Level 1 (high-level) evidence