Altitude sickness Q&A

What is altitude sickness?

Altitude sickness refers to the health problems that can happen when you travel to high altitudes (around 8,000 feet or higher above sea level). Altitude sickness can occur in the mountains or in high-altitude cities, like Mexico City or Denver.

Is all altitude sickness the same?

No, there are 3 types of altitude sickness:

1. Acute mountain sickness (AMS) is the most common type. It tends to make people feel like they have an alcohol hangover.
2. High-altitude cerebral edema (HACE) involves swelling of the brain. It's very serious and can be life-threatening if not treated right away.
3. High-altitude pulmonary edema (HAPE) involves fluid buildup in the lungs. It's also very serious and can be life-threatening if not treated right away.

What are the symptoms of AMS?

The symptoms of acute mountain sickness, which can happen within a day of traveling or climbing to a very high altitude, often include:

• Headache
• Feeling tired
• Feeling lightheaded
• Having no appetite
• Trouble sleeping
• Nausea, sometimes with vomiting
• Getting short of breath with exercise

What should I do if I have AMS?

• Stop and rest.
• Move to a lower altitude if possible, and don’t travel to a higher altitude until you feel better.
• For a headache, take aspirin, acetaminophen (e.g., Tylenol), or ibuprofen (e.g., Advil, Motrin).

You might be tempted to keep climbing, especially if you’re with other people. But it's important to rest so you don't get worse. If you’re with someone who has symptoms of altitude sickness, stay with them so you can get help if needed.

Can I prevent AMS?

Yes! The best way to prevent altitude sickness is to avoid moving quickly to a high altitude. If possible, increase your altitude little by little over several days to give your body time to adjust.

It's also helpful to:

• Avoid alcohol use while you’re adjusting to a high altitude
• Avoid difficult physical activities for the first few days at a high altitude
• If hiking, go to a higher altitude during the day and then go back down to a slightly lower altitude each night to sleep

Is there medication to prevent AMS?

Yes. If you’re planning a trip to a high altitude, we may prescribe a medication called Acetazolamide.

Common side effects of this medication include: nausea/vomiting, fatigue, and numbness/tingling/itching. It rarely causes serious reactions such as: anemia, electrolyte imbalances, rash, and anaphylaxis.

What are the symptoms of HACE?

The symptoms of HACE (swelling of the brain) usually start 1 to 3 days after traveling or climbing to a high altitude. They include:

• Extreme tiredness and weakness
• Problems with coordination (e.g., having trouble walking normally)
• Confusion and irritability
• Acting drunk

If you have any symptoms of HACE, call 911 or seek emergency care right away.

What are the symptoms of HAPE?

The symptoms of HAPE (fluid in the lungs) usually start 2 to 4 days after traveling or climbing to a high altitude. They include:

• Coughing
• Feeling breathless
• Trouble walking uphill

If you have any symptoms of HAPE, call 911 or seek emergency care right away.