Altitude Sickness: Prevention and Tips for Trekkers

Altitude sickness, or Acute Mountain Sickness (AMS), is a concern for anyone trekking above 2,500 meters. Understanding it is the key to a safe and enjoyable Himalayan trek. ## What is AMS? AMS occurs when your body struggles to adapt to reduced oxygen at high altitudes. It typically affects trekkers ascending above 3,000 meters too quickly. Mild AMS is common and manageable, but severe forms — High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE) — are life-threatening and require immediate descent. ## Symptoms to Watch For Mild AMS symptoms include headache, nausea, loss of appetite, fatigue, dizziness, and difficulty sleeping. These symptoms usually appear 6-12 hours after arriving at a new altitude. Severe AMS warning signs include worsening headache unrelieved by medication, vomiting, loss of coordination (ataxia), confusion, shortness of breath at rest, and a persistent cough producing frothy or pink sputum. ## The Golden Rule: Walk High, Sleep Low The most effective prevention strategy is gradual ascent. trek above your sleeping altitude during the day and descend to sleep at a lower elevation. The general guideline is not to increase your sleeping altitude by more than 300-500 meters per day above 3,000 meters. Include rest days (acclimatization days) every 3-4 days or after significant altitude gains. ## Hydration and Nutrition Drink 3-4 liters of water per day. Dehydration worsens AMS symptoms. Avoid alcohol and tobacco, as they impair acclimatization. Eat a high-carbohydrate diet — dal bhat, pasta, potatoes, and bread provide the energy your body needs to adapt. ## Medication Acetazolamide (Diamox) can help prevent and reduce symptoms of AMS by speeding up acclimatization. Consult your doctor before your trip about dosage (typically 125mg or 250mg twice daily starting one day before ascent). It is not a substitute for proper acclimatization, and it does not prevent severe AMS. ## When to Descend If symptoms worsen despite rest and medication, descend immediately — even 300-500 meters can make a significant difference. Never ascend with symptoms of AMS. Never leave someone with AMS alone. The only definitive treatment for severe AMS is descent. ## Rajkumar's Advice As a guide who has crossed Thorong La and Larkya La dozens of times, I tell every trekker: listen to your body. There is no shame in turning back or taking an extra rest day. The mountains will always be there. Your health comes first. A well-planned itinerary with built-in acclimatization days, proper hydration, and a knowledgeable guide are your best defenses against altitude sickness.