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Mountain Sickness: What To Do When It Happens and How To Avoid It

When I talk about mountain sickness, I am not talking about being homesick because you miss the comforts of your warm house and soft bed. Although I am certain that staying in stuffy and uncomfortable tents may lead to some sort of sickness, that type of sickness won’t be discussed in this post.

Mountain sickness, medically known as AMS (Acute Mountain Sickness) or Altitude Sickness is a serious illness which can affect hikers and mountain climbers who trek above 2,400m (~ 7,900 ft).

Such a captivating feeling being above the clouds. Here is a photo in Mt. Maculot, Batangas. It’s not a high peak but it is a steep climb, a great training ground for higher summits as it is only a 3hr drive from Manila.

In the Philippines, there are around 30 mountains which fall in this category. For a list of these mountains, click here.

I was made aware of AMS during my first trip to Mt. Pulag, the highest peak in Luzon at 2,926m (~ 9,600 ft) above sea level. I heard of horror stories of hypoxia (when the body does not absorb enough oxygen) wherein hikers had to turn back from the trek due to their body not acclimatizing to the thin air. It sounds daunting especially if you’ve been training for months to reach the peak.

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My first hand experience with AMS at Gokyo-Ri, en route to Mt. Everest Base Camp. At 5,380m (~ 18,000ft) above sea level, my lips, hands and face started to swell, and I had tingling sensations in my extremities. I lost my appetite, felt nauseous around dinner time, and got dizzy every time I went to bed. We had to take an extra rest day for my body to acclimatize.

Below are different categories of high altitude symptoms which you need to be learn before ascending to high summits:

Normal Altitude Symptoms

When you ascend, it is normal to experience bodily changes due to the thinning of the air. These shouldn’t alarm you but awareness should help you understand your body better. Normal altitude symptoms include difficulty sleeping due to periodic heavy breathing and sometimes having vivid dreams. Slight swelling in the hands and face, faster heart beats, getting tired faster and more constant urination are all symptoms caused by your body trying to adopt to the new environment. Any form of treatment is unnecessary at this stage.

Acute Mountain Sickness (AMS)

AMS has a wide array of symptoms, including feeling dizzy or light-headedness, headaches, loss of appetite, nausea or vomiting, increased heart rate even at rest, and shortness of breath. Symptoms can vary from mild, moderate to severe.


Treatment of AMS: If symptoms are moderate, descend 500m or more with a co-hiker. It is not advisable to descend alone. At this stage, the hiker who is experiencing moderate AMS may need oxygen (PAC), Acetazalomide (Diamox) and may even need to be carried back to lower altitudes.

High Altitude Cerebral Edema (HACE)

This is a critical stage of mountain sickness where the fluids reach the brain. Symptoms are similar to severe AMS, including a bad headache, vomiting, confusion and clumsiness. Sometimes a hiker affected by HACE can look like they are intoxicated with alcohol by the way they move and speak.

Treatment of HACE: Descend immediately. Possibly call for an emergency evacuation unit.

High Altitude Pulmonary Edema (HAPE)

Another critical illness is HAPE. This is when fluids get in the lungs of the hiker. This usually occurs within 4 days of arriving at an altitude over 2,400m (~ 7,900 ft). This can happen slowly or suddenly. Symptoms include being breathless at rest, feeling exhausted, coughing and inability to lay down flat.

Treatment for HAPE: Descend immediately (assisted or carried). Possibly call for an emergency evacuation unit.

Mountain Sickness Prevention Wisdom

Anyone can get hit with mountain sickness. It doesn’t matter how many times you have climbed, mountain sickness can affect any hiker or climber at any time. Everyone acclimatizes at different rates and it has nothing to do with physical fitness levels. There are many ways you can avoid getting affected by mountain sickness and I have listed a few tips below:

  1. Avoid ascending too fast

  2. Limit intake of alcohol, caffeine and sedatives

  3. Drink a lot of fluids (water, fruit juices, electrolytes)

  4. Wear the right gear (keep warm if it’s cold, keep dry if it’s wet)

  5. Avoid over exertion

  6. Sleep no more than 400m (~ 1,300ft) higher each night once you reach above 2,400m (~ 7,900 ft)

  7. Rest every 3 days or every 1,000m ascent

  8. Climb high, sleep slow. Always try to sleep at lower altitudes than what you’ve climbed.

  9. Keep medicine such as Acetazolamide (Diamox) in your first aid kit

For other hiking and travel tips, visit our page here!



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