Colorado Hunter Safety Course


Altitude Sickness

High Altitude

Altitude sickness occurs at higher elevations, generally beyond 6,000 to 8,000 feet. At higher altitudes air becomes thinner so as elevation increases, the amount of oxygen one gets in a breath decreases. Altitude sickness can affect anyone, even those who are accustomed to higher elevations.

There are three forms of altitude sickness. Acute Mountain Sickness (AMS) is the most common form and is considered the least severe. Its symptoms are very similar to a hangover and include headache, fatigue, dizziness, nausea or vomiting. The sudden onset of any of these symptoms should not be taken lightly. If this occurs, stop ascending and remain calm. Descend about 1,000 feet - this should help alleviate the symptoms - and remain at this elevation. If you still feel ill after descending, descend until you start feeling better, and seek medical attention.

High Altitude Cerebral Edema (HACE) is a rare but very serious condition where swelling of the brain can cause coma or death within hours. It is usually a result of failure to treat AMS, but can also present without any previous condition. The early symptoms include severe headache, confusion, hallucinations or loss of coordination/stumbling. Anyone who experiences these symptoms should descend immediately, and seek medical help as soon as possible.

High Altitude Pulmonary Edema (HAPE) can occur after a few days above 8000 feet. It is an accumulation of fluids in the lungs which cause severe shortness of breath, a wet cough, bluish skin, eventually coma and potentially death. Anyone experiencing these symptoms should be descended immediately, and seek medical help as soon as possible.

SAFETY FIRST! Listen to your body! If you feel ill, don't shrug it off. Descend in elevation, and seek medical help if the symptoms get worse or don't go away.


You can help prevent Altitude Sickness by following these steps:

  • Stay well hydrated.
  • Eat foods that are high in carbohydrates and low in fat and salt content.
  • If you are accustomed to lower elevations and arrive at an area of higher elevation, take a day or two to rest before doing any activities such as hunting or hiking.
  • If you start to get tired or are out of breath, take a break. Pushing yourself will only make matters worse.
  • Avoid climbing more than 3,000 feet per day. If you are at an elevation of 12,000 feet or higher, do not climb more than 1,000 feet per day.
  • Do not take sleeping pills - these can slow your rate of breathing and lead to oxygen deprivation.
  • Sleep at a lower elevation. For example, if you are hunting at 10,000 feet, you should sleep around 8,500 feet. This will help prevent your blood oxygen level from lowering during sleep.
  • In continuously increasing elevations, spend at least two consecutive nights at the same elevation, every three days.

IMPORTANT! The most effective way to prevent Altitude Sickness is to acclimate yourself to the environment. Give your body a few days to adjust to the higher elevations before setting out on your hunt.