Altitude Illness

Altitude Illness

Almost every year people die from altitude illnesses in the Cordillera Blanca. It will take four minutes to read the following information and it could save your life…

What is considered “altitude”?

·2400m – 3600m “High Altitude” About 20% of people who ascend quickly and sleep above 2400m suffer mild altitude illness.

·3600 – 5500m “Very High Altitude” Over 50% of people develop altitude illnesses if they quickly ascend to 3500 meters, and everyone does if they ascend quickly to 5000 meters.

·5500 + “Extremely High Altitude” Above 7500 meters is referred to as the death zone. 4% of all people who go that high die from altitude illness!

The affects altitude has on us:

1. Less Oxygen

The higher we go, the thinner the air is due to less atmospheric pressure. At 3600m there are 40% fewer oxygen molecules per breath then at sea level. Our bodies must adjust to this before we can be happy at higher altitudes. Meanwhile, you may be out of breath at the top of the stairs, feel tired and “hung over” and your sleep pattern may be affected, often waking up several times at night.

2. Less Atmospheric Pressure:

The affects of this are not completely understood, even by really smart people. In some cases it causes fluid to leak from the blood capillaries causing swelling.


Despite this dubious news of leaking capillaries and sleepless nights, there still is hope! The human body has a remarkable ability to adapt to higher elevations through a process called “acclimatization” which:

  • Increases respirations.
  • Produces more red blood cells to make the blood more efficient in distributing oxygen.
  • Increases pressure in the arteries of the lungs, forcing blood into parts of the lung that are not used at sea level (making them more efficient).

What you need to do to help your body with the task of acclimatization:

  • Ascend slowly. Go higher during the day and then return to a lower elevation for the night, increasing your sleeping elevation by 500m per night.
  • Drink at least 3 liters of water a day and eat a high carbohydrate diet; this makes your body 70% more efficient in the acclimatization process.

As everyone acclimatizes at a different pace regardless of physical fitness or how great of a climber they are, while at altitude you should monitor yourself and your group for signs of the following illness:


Acute Mountain Sickness is the most common sign that your body has not adapted to a higher altitude.

Symptoms of AMS: (one or more)

1.Headache, 2.Fatigue, 3.Loss of appetite, 4.Nausea or vomiting, 5.Inability to sleep.

Treatment for AMS:

Do not ascend. Consider descending. Monitor for onset of HACE and HAPE. Do not leave this person alone. Other things that help are Ibuprofen and warm fluids.


High Altitude Cerebral Edema. This is an advanced form of AMS. Your brain is swelling, causing confusion and weird behavior. This is LIFE THREATENING and must be treated with immediate action.

Symptoms of HACE:

1.All the same symptoms of AMS plus.

2.Change in mental status – The patient acts “differently” or out of character.

3.Ataxia –is a decrease in balance and coordination. Have the patient walk heel to toe along a straight line – anyone who has difficulty balancing at altitude should be suspected as having HACE.

Treatment for HACE:

Immediate descent to at least where patient slept without symptoms of any altitude illness. Don’t wait around for morning, or for your spaghetti to boil. If the Ataxia gets too bad the patient can’t walk making the decent more time consuming.


High Altitude Pulmonary Edema. This is LIFE THREATENING. Your lungs are filling with fluid that has leaked out of your capillaries. AMS does not always precede HAPE.

Symptoms of HAPE:

1.Shortness of breath at rest, 2.Extreme fatigue, 3.Persistent productive cough, 4.Gurgling sounds from the lungs (advanced cases)

The treatment of HAPE is the same as HACE. Immediate decent.

So… Get out there and enjoy the incredible areas around Huaraz but take your time and be safe!

By: Ted Alexander, is the head guide for Skyline Adventures and has been climbing and guiding in the Cordillera Blanca for 12 years.