272 ROACH, BARTSCH, et
THE LAKE LOUISE ACUTE
R.C. Roach, P. Bartsch, P.H. Hackett, O. Oelz
and the Lake Louise AMS Scoring Consensus Committee*
In 1991, the Lake Louise Consensus Committee met and agreed on diagnostic
criteria and a scoring system for the symptoms and signs
acute mountain sickness!.
The goal was to provide enough sensitivity, specificity and flexibility to allow use
in many different settings and to facilitate comparisons
results among all studies
by using this instrument. Since then investigators have used the Lake Louise AMS
scoring system in different settings at different altitudes in several countries. The
previous standard, the Environmental Symptoms Questionnaire (ESQ), has 67 items,
takes time and patience for subjects to complete, and has been resisted by many
researchers2• In contrast, the Lake Louise AMS scoring system takes only a few
minutes to complete and score. Several groups have reported comparable results
regarding sensitivity and specificity between the Lake Louise AMS scoring system
Therefore, we recommend that this scoring system be adapted as
the standard for acute mountain sickness research.
INSTRUCTIONS: The Lake Louise AMS Scoring System
The Lake Louise scoring system consists
a short self-report questionnaire,
sufficient in itself,
to which may be added an additional clinical assess-
ment. The AMS Self-report score
responses to 5 questions; the find-
ings can be verified by interview
the clinical research setting. The Clinical Assess-
ment score is the interviewer's rating
three signs: mental status, ataxia and
peripheral edema. This score is added to the AMS Self-report questionnaire score.
An optional question
recommended to assess functional consequences
symptoms and signs. The scoring system
designed to allow use in both large surveys
and in smaller clinical trials.
Diagnostic Criteria for Acute Mountain Sickness
based on a recent gain in altitude, at least several hours
at the new altitude, and the presence
headache and at least one
*The Lake Louise AMS Scoring System Consensus Committee: Almas Aldashev, CIS; Buddha Basnyat,
Nepal; A.R. Bradwell, UK; Charles Clark, UK; Geoff Coates, Canada; Allen Cymerman, USA; Allen
Ellsworth, USA; R.F. Fletcher, UK; Eugene Gippenreiter, Russia; Colin Grissom, USA; Ben Honigman,
USA; Charles Houston, USA; Herb Hultgren, USA; Bengt Kayser, Switzerland; Toshio Kobayashi, Japan;
Gig Leadbetter, USA; Marco Maggiorini, Switzerland; N.D. Menon, India; Jim Milledge, UK; C. Carlos
Monge, Peru; Michiro Nakashima, Japan; Dick Nicholas, USA; Drummond Rennie, USA; Jean Paul
Richalet, France; Paul Rock, USA; Roberto Rodriguez Guaita, Chile; David Shlim, Nepal; John Sutton,
Takei, Japan; Gou Ueda, Japan;
1993 Roach RC, Bärtsch P, Oelz O, Hackett PH. The Lake Louise Acute
Mountain Sickness Scoring System. In: Sutton JR, Houston CS, Coates G,
Editors. Hypoxia and Molecular Medicine. Burlington, VT: Queen City Press;
1993. p. 272-274.
LAKE LOUISE AMS SCORING SYSTEM
symptoms: gastrointestinal upset (anorexia, nausea,
vomiting), fatigue or weakness,
lightheadedness and difficulty sleeping. A score
the AMS Self-report questionnaire alone,
in combination with the Clinical
Assessment score constitutes AMS.
A) Self-report questionnaire. This portion
the scoring system
and should be reported as a separate score. Each
the following five questions
is asked with the corresponding 0 to 3 rating
some studies, the
question "Difficulty sleeping" will not
relevant (e.g. rapid one day ascent) and
can be omitted. The sum
the responses on these questions is then calculated as
the AMS Self-report score.
is recommended that this score be reported separately,
even when used with the Clinical Assessment score. This procedure will allow the
severity among the majority
studies. All will have the AMS Self-
report score, some will have both the AMS Self-report score and the Clinical Assess-
Headache. 0 No headache
I Mild headache
2 Moderate headache
3 Severe headache, incapacitating
Gastrointestinal symptoms. 0 No gastrointestinal symptoms
I Poor appetite or nausea
2 Moderate nausea or vomiting
3 Severe nausea & vomiting, incapacitating
3. Fatigue and/or weakness. 0 Not tired or weak
I Mild fatigue/weakness
2 Moderate fatigue/weakness
3 Severe fatigue/weakness, incapacitating
Dizziness/l ightheadedness. 0 Not dizzy
I Mild dizziness
2 Moderate dizziness
3 Severe dizziness, incapacitating
Difficulty sleeping. 0 Slept
I Did not sleep as well as usual
2 Woke many times, poor night's sleep
3 Could not sleep at
Clinical Assessment. This portion
the scoring system contains information
examination. The Clinical Assessment score
scores on the follow-
ing three questions.
274 ROACH, BARTSCH, et
mental status. 0 No change
7. Ataxia (heel to toe walking) 0 No ataxia
1 Maneuvers to maintain balance
2 Steps off line
3 Falls down
4 Can't stand
Peripheral edema. 1 No peripheral edema
1 Peripheral edema
2 Peripheral edema at two or more locations
Score. The functional consequences of the
should be further evaluated
one optional question asked after the AMS Self-report
questionnaire. Alternatively, this question may be asked by the examiner
Assessment is performed.
you had any symptoms, how did they affect your activity?
o No reduction
1 Mild reduction
2 Moderate reduction
3 Severe reduction
activity (e.g. bedrest)
I. The Lake Louise Consensus on the definition and quantification of altitude illness. In: Hypoxia
and Mountain Medicine, J.R. Sutton, G. Coates, C.S. Houston, editors. Burlington, YT: Queen
City Printers Inc., 1992, p. 327-330.
2. SAMPSON, J.B.,
CYMERMAN, R.L. BURSE, J.T. MAHER, P.
ROCK. Procedures for
acute mountain sickness. Aviat. Space Environ.
54(12): 1063-1073, 1983.
3. HONIGMAN, B., J.L. ATKINS, R.C. ROACH, C.S. HOUSTON (Abstract). Acute mountain
the elderly at moderate altitude. In: Proceedings
the Eighth International Hypoxia
Symposium, Lake Louise, Canada, 1993.
4. BARTSCH, P.,
YOCK, O. OELZ. AMS
and HAPE scoring
the Alps (Abstract).
the Eighth International Hypoxia Sym-
posium, Lake Louise, Canada, 1993.
5. ELLSWORTH, A., T. DUNCAN,
GOLDBERG, L. JOHNSON, P. HACKETT. Measuring
acute mountain sickness using the Lake Louise Consensus Questionnaire (Abstract).
the Eighth International Hypoxia Symposium, J.R. Sutton,
Coates, C.S. Houston, editors.
RUBY, D. LIUM. The effect
intermittent altitude ex-
posure on acute mountain sickness (Abstract).
Chapter, Am. Coli. Sports. Med. 1992.