The Lake Louise Acute Mountain Sickness Score (LLAMSS) calculator is designed to evaluate the severity of acute mountain sickness based on responses to four symptom-related questions. Each question aims to capture the intensity of symptoms commonly associated with altitude sickness: headache, gastrointestinal symptoms, fatigue or weakness, and dizziness or lightheadedness. Users select from predefined options for each symptom, with these options then converted into a numerical score.

The scoring is as follows:

- Headache:
  - None = 0
  - Mild = 1
  - Moderate = 2
  - Severe/incapacitating = 3
- Gastrointestinal symptoms:
  - Good appetite = 0
  - Poor appetite or nausea = 1
  - Moderate nausea or vomiting = 2
  - Severe/incapacitating nausea and vomiting = 3
- Fatigue and/or weakness:
  - None = 0
  - Mild = 1
  - Moderate = 2
  - Severe/incapacitating = 3
- Dizziness/lightheadedness:
  - None = 0
  - Mild = 1
  - Moderate = 2
  - Severe/incapacitating = 3

To determine the AMS score, the scores for each symptom are summed. The total can range from 0 to 12, with higher scores reflecting greater symptom severity. Interpretation of the AMS severity is based on the total score:

- 3 to 5 indicates Mild AMS
- 6 to 9 suggests Moderate AMS
- 10 to 12 signifies Severe AMS
- 0 to 2 indicates that AMS severity cannot be fully assessed

By using this system, users can gain insights into their condition, potentially guiding decisions about seeking medical attention or adjusting altitude exposure.

The 2018 Lake Louise Acute Mountain Sickness Score (LLAMSS) is a clinical calculator used to assess the severity of Acute Mountain Sickness (AMS) in individuals who have recently ascended to high altitudes. This scoring system is applicable to climbers, hikers, skiers, or any individuals who are at high altitudes, typically above 2,500 meters. The LLAMSS is clinically useful in diagnosing AMS, monitoring its progression, and guiding treatment decisions. It takes into account various symptoms including headache, gastrointestinal symptoms, fatigue, dizziness, and difficulty sleeping. The score ranges from 0 to 12, with higher scores indicating more severe AMS. There are no specific exclusion criteria for its use, but it should be noted that this score is not designed to diagnose other altitude-related illnesses such as high altitude cerebral edema or high altitude pulmonary edema.