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.

What is the cause?

The air at high altitudes has less oxygen than at sea level, so it’s harder for your body to get as much oxygen as it needs. Not getting enough oxygen can cause illness.

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 to a high altitude and start high-energy physical activity right away, before your body has time to adjust, you are at more risk for altitude sickness.

Some health problems increase the risk that you will get sick at high altitude. 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?

At first, you may 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 physical activity

Serious types of altitude sickness are:

• Fluid in the lungs, a problem called high-altitude pulmonary edema

  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.

• Swelling of the brain, a problem called high-altitude cerebral edema

  When you have high-altitude cerebral edema, 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 high-altitude edema may start out as a milder form of altitude sickness and develop over several days or you may suddenly become seriously ill. These forms of altitude sickness can cause death.

How is it diagnosed?

Your healthcare provider will examine you and ask about your symptoms, activities, and medical history.

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 recover at the lower altitude. If your body adjusts and your symptoms go away, you may try going back to a higher elevation. If you cannot go to a lower elevation right away, you may need to see a healthcare provider. You may be given oxygen or medicine to treat your symptoms.

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?

Here are some things you can do to help keep from getting sick at high altitudes:

• Take a trip up into the mountains in stages. For example, if you are starting at sea level, spend the first night at an altitude no higher than 6,000 feet.
• Take 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 can make you breathe less deeply while you sleep, making it even harder for your body to get oxygen.
• Talk to your healthcare provider about medicines that might help prevent altitude sickness.