The 2018 Lake Louise Questionnaire scores three symptoms of acute mountain sickness (AMS). It is the standard clinical tool for AMS in field research and mountain medicine. Score yourself or a companion after a recent altitude gain, and get an interpretation with descent guidance.
Symptoms in the last 24 hours
Result
About this calculator
The Lake Louise Score is a self-report questionnaire for acute mountain sickness (AMS). It was first developed at a consensus conference in Lake Louise, Canada in 1991, and revised in 2018.
The 2018 revision dropped the sleep item that appeared in the earlier four-item questionnaire. High-altitude sleep is disrupted by periodic breathing and hypoxia even in fully acclimatised climbers, so a sleep score conflates acclimatisation with AMS and is not diagnostic. The revised score uses three core items: headache, gastrointestinal symptoms, and fatigue/weakness. A supplementary dizziness/lightheadedness item is included here for completeness following the published 2018 questionnaire.
Diagnostic prerequisites. AMS is diagnosed in a person who has recently ascended to altitude (typically above about 2500 m) and has a headache PLUS a total score of at least 3 with at least one other symptom present. A total score without a headache does not diagnose AMS.
Score bands. 3-5 mild AMS, 6-9 moderate AMS, 10-12 severe AMS. Moderate scores generally require halting further ascent; severe scores require descent.
Warning signs. Ataxia and altered mental status are cardinal signs of high altitude cerebral oedema (HACE), and breathlessness at rest with a wet cough suggests high altitude pulmonary oedema (HAPE). Both are medical emergencies; immediate descent is the definitive treatment.
Citation. Roach RC, Hackett PH, Oelz O, Bartsch 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 19(1):4–6 (2018).
Clinical practice guideline. Luks AM, Auerbach PS, Freer L, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness & Environmental Medicine 30(4S):S3–S18 (2019).