Complete Guide to Altitude Sickness Prevention
What is Altitude Sickness?
Altitude sickness, medically known as Acute Mountain Sickness (AMS), is a physiological response that occurs when the human body enters high-altitude areas too quickly. Lhasa sits at 3,650 meters, while Everest Base Camp reaches 5,200 meters. At these altitudes, atmospheric oxygen pressure is only 60-70% of sea level.
Common Symptoms
Altitude sickness typically appears 6-12 hours after arrival. Common symptoms include headache, dizziness, nausea, loss of appetite, fatigue, sleep disturbance, and mild chest tightness. Most cases are mild and resolve within 1-3 days. However, severe cases may develop into high altitude pulmonary edema or cerebral edema, which require immediate medical attention.
Pre-departure Preparation
Physical fitness does not prevent altitude sickness. However, maintaining regular sleep, avoiding excessive fatigue, and quitting smoking can help. Consult a doctor if you have heart disease, high blood pressure, chronic lung disease, or severe anemia. Acetazolamide (Diamox) is a medically approved preventive medication that can be prescribed by your doctor.
First Three Days at High Altitude
Rest completely on your first day. Avoid sightseeing and strenuous activity. Stay well-hydrated by drinking 2-3 liters of water daily. Avoid alcohol, strong tea, and coffee. Eat light, easily digestible food. Keep warm as temperature drops significantly at night.
During Your Journey
Follow the gradual ascent principle. Carry a portable pulse oximeter to monitor blood oxygen levels. Brief oxygen use can relieve symptoms, but avoid dependency. Normal blood oxygen saturation is 95-99% at sea level, 85-92% at altitude is acceptable.
When to Seek Help
Seek immediate help if you experience: severe persistent headache unrelieved by medication, vomiting or inability to eat/drink, severe breathing difficulty, confusion or loss of coordination, bluish lips or face, or coughing up pink foam. Immediate descent to lower altitude is the most effective treatment.
Common Myths
Young, fit people are not immune to altitude sickness. Rhodiola rosea may help slightly but is not a reliable preventive. Previous visits don't guarantee you won't have symptoms this time. Don't ignore worsening symptoms—seek help if they persist beyond 24 hours.