Environmental emergencies: What is altitude sickness?

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Altitude sickness occurs if there is inadequate oxygen in the air at high altitudes. This condition triggers symptoms such as difficulty sleeping, headache and appetite loss. It is likely to occur among those who are not used to high altitudes.

Mild cases of altitude sickness are quite common. Even experts do not know who are at risk and who are not. Neither the fitness level nor being female or male plays a role whether one will end up with altitude sickness.

Remember that altitude sickness can be dangerous. It is important to take special care when going on hiking or camping in high-altitude areas or have plans to spend a vacation in high-altitude countries.

What are the causes?

Air is “thinner” at areas with high altitudes. If an individual move up too quickly, the body could not receive as much oxygen it requires, thus breathing is increased. This can cause headaches and other symptoms of altitude sickness. Once the body is accustomed to the altitude level, the symptoms eventually settle.

What are the indications?

Altitude sickness
Headache that is throbbing and becomes worse during night time and upon waking up.
  • Headache that is throbbing and becomes worse during night time and upon waking up
  • Diminished appetite
  • Feeling sick in the stomach and vomiting
  • Feeling tired and weak. In severe cases, the individual does not have the energy to eat, dress or do anything.
  • Dizziness
  • Waking up during the night and not able to sleep well.

The symptoms can range from mild to severe. They might not start until a day after reaching a high altitude.

Altitude sickness can affect the lungs and the brain. Once this occurs, symptoms include:

  • Confusion
  • Ataxia or unable to walk straight
  • Feeling faint
  • Bluish or grayish lips or fingernails

These symptoms indicate that the condition is severe and can be deadly.


The ideal treatment for altitude sickness is to move down to a lower altitude. If the individual has mild symptoms, he/she can stay in that level and allow the body to get used to it. The symptoms often occur if an individual has just arrived at a mountain resort from a lower altitude.

Oxygen can also be used or a specially designed pressure chamber to manage altitude sickness.

When staying at high levels, it is vital to rest. Limit any activity or walking and drink more water, but avoid alcohol. The individual should not move to the higher level until the symptoms settle which can take 12 hours up to 3-4 days.

Over-the-counter pain medication such as ibuprofen or naproxen can be given for relief to the headaches. Other medications to reduce the sensation of being sick in the stomach or other symptoms can be given as well.

The doctor might prescribe acetazolamide which speeds up the acclimatization of the body to higher altitude. Dexamethasone and nifedipine can also be used for altitude sickness.

Quick Note / Disclaimer

The material posted on this page on altitude sickness is for learning and educational purposes only. To learn to recognize and manage environmental emergencies including altitude sickness, register for a first aid and CPR course with one of our training providers.

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The information posted on this page is for educational purposes only.
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