Altitude sickness: What are the indications?

Altitude sickness is a condition defined by a group of generalized symptoms that are triggered by moving to areas with high altitude too rapidly.

Who are at risk?

Altitude sickness can affect individuals of all ages moving to high altitudes who do not allow the body sufficient time to adjust to the changes in the air pressure and oxygen level.

If one rapidly moves up to areas with higher altitude, the more likely for the condition to develop. The condition is likely to arise when a climb is difficult in which more energy is required.

Climbing rapidly will not allow the body adequate time to adjust to the reduced air pressure and reduced level of oxygen in the air at areas with higher altitudes. The body acts by triggering an increase in the breathing rate. This improves the blood oxygen but not to its average levels. The body should adjust to functioning with reduced oxygen than normal. Once the body does not have sufficient time to adjust, the symptoms of altitude sickness manifests.

Altitude sickness

The usual signs of altitude sickness include nausea, headache, vomiting and lightheadedness.

What are the signs?

The usual signs of altitude sickness include nausea, headache, vomiting and lightheadedness. It is important to note that the various levels of altitude sickness have varying symptoms.

Mild, brief altitude sickness

  • Fatigue
  • Dizziness
  • Appetite loss
  • Shortness of breath
  • Sleeping problems
  • Generalized loss of energy

The symptoms subside in 1-2 days as the individual is getting used to the altitude level.


This type is intense and could not be relieved with over-the-counter drugs. Weakness, fatigue and shortness of breath become worse instead of improving over time.

These is loss of coordination and difficulty walking along with an intense headache, nausea, vomiting and congestion or tightness in the chest. Normal activity is also difficult, but the individual can still walk on his/her own.


This form of altitude sickness includes shortness of breath while at rest, confusion, inability to walk and buildup of fluid in the lungs and/or brain. Other symptoms that might be present include gray, whitish or bluish skin tone and cough. This is an emergency and the individual must be moved to an area with lower altitude right away.

Disclaimer / More Information

The information posted on this page on altitude sickness is for learning and educational purposes only. To learn to recognize the indications, register for first aid training at one of our training centers located throughout Canada. The training centers are in Edmonton, Calgary, Vancouver, Kelowna, Saskatoon, Victoria, Surrey, Mississauga, Winnipeg, Red Deer, Toronto, Ottawa and Halifax.