Altitude Sickness

What is altitude sickness?

Altitude sickness is a problem you can have when you travel to a high altitude. It happens most often at altitudes over 8,000 feet above sea level. It is also called mountain sickness.

Especially serious types of altitude sickness are:

• fluid in the lungs, a problem called high-altitude pulmonary edema
• swelling of the brain, a problem called high-altitude cerebral edema

These forms of altitude sickness can be fatal.

What is the cause?

The air at high altitudes has less oxygen than at sea level. Your body has to work harder to get oxygen. After you have been at high altitude for several days, your body makes changes that make it easier to get oxygen from the thinner air. If you travel from sea level to mountain altitudes of 6,000 to 10,000 feet and start vigorous physical activity right away, you are at more risk for altitude sickness because your body has not had time to adjust.

Certain health problems increase the risk of altitude sickness. These include:

• not drinking enough fluids
• smoking
• not enough red blood cells in your blood (anemia)
• chronic lung problems, such as asthma or emphysema
• drinking too much alcohol

Being physically fit does not protect you against altitude sickness.

If you have had altitude sickness before, there is a good chance you will have it again.

What are the symptoms?

With altitude sickness, you may first feel like you have the flu or a hangover. You may have:

• headache
• tiredness
• loss of appetite
• nausea or vomiting
• dizziness
• trouble sleeping
• trouble breathing during exercise

If you have pulmonary edema, excess fluid builds up in your lungs. You may get short of breath and start coughing. It may get very hard to breathe. You may cough up pink mucus.

When you have high-altitude cerebral edema, your brain swells. You may become confused and disoriented. You may feel weak, lose your sense of balance, or have trouble seeing. You could go into a coma and possibly die within hours of the first symptoms.

Pulmonary or cerebral altitude edema may start out as a milder form of altitude sickness and develop over several days. But sometimes the edema happens without the usual symptoms of mountain sickness.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you.

How is it treated?

The most important treatment for altitude sickness is to go down to a lower elevation. For example, if you are at 8,000 to 9,000 feet, you may need to travel down to an elevation of 5,000 feet or lower to help your symptoms go away. It may take 1 to 3 days for your body to adjust to the lower elevation. If your body adjusts and your symptoms go away, you may try going back to a higher elevation. If it is not possible for you to immediately go down to a lower elevation, you may need to be given oxygen or take medicine prescribed by your healthcare provider.

If you have had fluid in your lungs or brain swelling from altitude sickness, you should not go back to the higher altitude.

How can I take care of myself and prevent altitude sickness?

• Take a trip into the mountains a little at a time. For example, if you are starting from sea level, spend the first night at an altitude of 5,000 to 6,000 feet if possible.
• Ease into your physical activity by taking it easy the first day or two.
• Drink plenty of fluids, such as water or sports drinks.
• Don’t smoke. Smoking makes it harder for your body to get oxygen.
• Don’t take sleeping pills. They may cause shallow breathing at night, making it harder for your body to get oxygen while you sleep.
• Talk to your healthcare provider about medicines that might help prevent altitude sickness.