Altitude Sickness - Prevention, Symptoms & What to Do

Altitude sickness can affect anyone above 2,500m. Here's what you need to know: how to prevent it, recognise symptoms, and respond if you or a fellow trekker is affected.

Altitude sickness (Acute Mountain Sickness, AMS) occurs when you ascend too quickly. Your body needs time to adapt to lower oxygen. Symptoms include headache, nausea, fatigue, dizziness, and loss of appetite. In severe cases, it can progress to HACE or HAPE—both life-threatening.

Prevention is key. Ascend gradually: don't gain more than 300–500m of sleeping altitude per day above 3,000m. Stay hydrated. Avoid alcohol and smoking. Some trekkers use Diamox (acetazolamide) after consulting a doctor—it helps acclimatization but isn't a substitute for slow ascent.

Our itineraries build in acclimatization days. On EBC, we rest in Namche and Dingboche. On Indian treks, we plan gradual gains. Listen to your body—if you feel unwell, don't push. Descend if symptoms worsen.

Recognise warning signs: severe headache that doesn't improve with rest, vomiting, confusion, difficulty walking. If someone shows these, descend immediately. Altitude sickness improves with descent—don't wait.

At Trekkers Heaven, our guides are trained to spot early symptoms and respond. We carry oximeters and first-aid kits. Your safety is our priority. Trek smart, trek slow, and enjoy the mountains.