From the Guidelines
Altitude sickness symptoms typically include headache, nausea, vomiting, fatigue, dizziness, and sleep disturbances, and can progress to life-threatening conditions such as high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) if not properly managed. These symptoms usually begin within 6-24 hours of ascending to high altitude (typically above 8,000 feet) 1. According to a recent study published in Sports Medicine in 2024, the risk of acute mountain sickness (AMS) steeply rises when unacclimatised individuals are exposed to increasing altitude, affecting more than 50% of them at altitudes above 4500 m 1.
Symptoms of Altitude Sickness
- Headache
- Nausea
- Vomiting
- Fatigue
- Dizziness
- Sleep disturbances More severe symptoms may include:
- Shortness of breath
- Decreased coordination
- Difficulty walking
- Confusion
- Persistent cough In its most serious forms, altitude sickness can progress to HAPE with symptoms of extreme shortness of breath, chest tightness, and pink frothy sputum, or HACE with symptoms of severe headache, confusion, hallucinations, and loss of consciousness 1.
Management of Altitude Sickness
If you experience symptoms of altitude sickness, it's best to descend to a lower altitude, rest, stay hydrated, and consider medications like acetazolamide (Diamox) which can help speed acclimatization. Proper acclimatization, gradual ascent, staying hydrated, and avoiding alcohol and smoking can also help prevent high altitude illness, including acute mountain sickness 1. Additionally, prophylactic medications like acetazolamide can be effective, but individuals should be aware of potential side effects and have proper corrective measures in place 1.
From the Research
Symptoms of Altitude Sickness
- Acute mountain sickness (AMS) is a common occurrence for travel to high altitudes, with symptoms including headache, sleep disturbance, and fatigue 2, 3, 4, 5
- High-altitude cerebral edema and high-altitude pulmonary edema are more serious syndromes that can occur when the hypoxic stress outstrips the subject's ability to acclimatize 2, 4
- The susceptibility of an individual to high-altitude syndromes is variable but generally reproducible, with factors such as rate of ascent and individual health playing a role 2, 5
- Symptoms of AMS can be measured using the Lake Louise Questionnaire (LLQ), with a score of >3 indicating acute mountain sickness 3
Prevention and Treatment
- Slow ascent is the best approach to preventing altitude-related illness, but this is not always practical 2, 5
- Acetazolamide is a commonly recommended medication for the prevention and treatment of AMS, with ibuprofen also showing efficacy in some studies 6, 3, 5
- Descent of more than 300 m as soon as possible is recommended for the immediate management of serious illness, along with oxygen supplementation if available 2, 4
- Pharmacological intervention, including the use of dexamethasone and nifedipine, may also be necessary in some cases 6, 2, 4