I absolutely love the Himalayas in Nepal. They are the only remote place on this planet I’ve returned to four times, because of their sheer beauty. If they were smaller and furrier, I would hug them all day long. But those high altitudes have a dark side. The human body has problems functioning properly above altitudes of 1,830m (6,000 ft), and the higher you go, the more problems arise. The formal term for this is acute mountain sickness (AMS). It can start as simply as a headache and can, in some cases, lead to death.

So how do we get AMS? Science has not plotted the line from what likely causes AMS (decreased oxygen at higher altitudes) to the exact onset of symptoms. We also can’t predict who will get AMS before they head to high altitudes. In-shape athletes have shown symptoms two hours after an express trip to 2,440m (8,000 ft), while couch potatoes had no problem.

The Trail To Mount Everest, Sagarmatha National Park, Nepal

We do however, know the conditions that bring on AMS – namely, ascending too quickly above 2,440m (8,000 ft). Trekking in the Himalayas, for instance, should be done at a pace of only 460m (1,500 ft) in altitude gain per day, with a rest day (sleeping at the same altitude for two nights) every third day. Trekkers should also sleep at an altitude lower than their highest altitude that day. Pushing 610m (2,000 ft) per day with no rest stops greatly increases the chances for AMS.

Symptoms of AMS begin with a headache and slight nausea, sometimes referred to as mountain sickness. Other symptoms then start to manifest themselves including loss of appetite, dizziness, sleeplessness, fatigue or vomiting. This is when medical attention becomes needed.

Trekkers in a line in the mountains

The onset of AMS symptoms can be fairly common to most lowland travellers in the Himalayas and are not instantly cause for alarm. The important aspect to monitor is if the symptoms are getting better or worse. If they’re getting better, you can proceed with caution; if they’re getting worse however, the one sure-fire cure is to descend. I’ve seen many first time travelers shrug off the symptoms as par for the course and continue up, not wanting to “miss out” on their vacation or goals. This puts travellers in peril that need not happen. If you feel a headache coming on, take a break, drink more water and maybe take some pain-killers. If symptoms persist, it’s time to change course and listen to your body. A rest day at a lower altitude might be all you need, but if you push it and develop more serious symptoms, your holiday (and maybe more) is over.

Tips for helping lessen the development of AMS include the following:

1. Travel with an experienced, trained guide with whom you can communicate easily. A good guide will keep track of your energy level, cognitive ability and appetite. Don’t skimp on a cheap guide.

2. Go slow. Do not compare your pace to sherpas or porters on the trail who have adapted to these conditions. Again, this is when a good guide is vital as they won’t push you beyond your limit just to keep the group going.

3. Hydrate more than you think you need to. The average heart rate of a trekker at rest at 12,000 ft. is close to that of their jogging heart rate at sea level. Just sitting there your heart is beating faster and you are breathing a lot more, which causes water-loss. Drink lots of water.

4. Consider a drug called Diamox before leaving home. While it does have some side effects, (which is why you should take it before arriving) it helps some trekkers.

5. Pressure breathing helps. Instead of just your normal panting, force the air out of your lungs to take good, deep breaths.

6. Rest and enjoy the view.

7. Take acclimatization days to help your body acclimatize by going higher than where you sleep. This means pushing maybe 1,500’ higher and then returning back to your lodge or camp.

8. Catch signs early and monitor them. In the past, I’ve used a pulse-oximeter to monitor those trekking with me, in addition to general questions and observation. This simple device (about USD $50 for a good one) clamps on a finger and monitors pulse as well as the saturation of oxygen in blood. I start this in Kathmandu before we head up as a baseline and check each morning and night, typically at meals. It’s just another tool to see if trekkers are getting enough oxygen or if they have symptoms that are worsening.

Tent Camp In Front Of Cloud Shrouded Thamserku And Kangtega, Nepal.

The good thing about AMS is you can stop worrying about it once you have reached your highpoint and are heading back to the lowlands. If you are interested in learning more, more information can be found at Himalayan Rescue Association Nepal, which mans an aid station en route to Everest Basecamp.

No matter how fit you are or how much you’ve trained, AMS can strike and you won’t know until you get there. It’s important to know the symptoms and what to do to ensure you have a safe and enjoyable holiday.

Stay safe!


Getting There

Ready to experience all that Nepal has to offer? G Adventures runs a wide range of departure dates and activities to Nepal that cater for different tastes. We’re thrilled at the prospect of showing you this wonderful planet of ours in a way you’ve never seen it — check out our small group trips here.