You’re all set to enjoy a long-awaited trip to the mountains. But after your flight lands and you arrive at your mile-high vacation spot eager for some hiking or sightseeing, you suddenly feel overcome by fatigue and dizziness.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Chalking it up to the stress of traveling, you opt for a quick cat nap before adventuring. Only you toss and turn, unable to sleep from the massive headache that’s arrived seemingly out of nowhere. What’s going on?
The answer might be as simple as altitude sickness, says pulmonologist Humberto Choi, MD.
Altitude sickness, also called acute mountain sickness, happens when your body is unable to adapt to a low-pressure, low-oxygen environment — typically at about 8,000 feet above sea level. This can cause breathing issues and a host of other symptoms which can range from very mild to life-threatening.
What causes altitude sickness?
The pressure in the air — barometric pressure — drops at higher elevations. There is also less oxygen in the air at these elevations. If you climb in elevation too quickly, your body doesn’t have time to adjust to less oxygenated air found at higher elevations. You’re forced to breathe more rapidly to compensate. This can cause hangover-like symptoms — dizziness, headache — even though you didn’t indulge the evening before.
Who’s at risk?
Altitude sickness can affect anyone, but some factors put you more at risk. These factors include:
- What elevation you live at normally vs. how high you venture to. If you normally live at lower elevations, such as New York City with an elevation of 33 feet, you’re more likely to feel the effects of higher elevations once there.
- How quickly you move to higher elevation. An abrupt change to a higher elevation — such as flying from low elevation to higher — seems to have more of an effect. Flying causes a sudden shift in elevation that makes it harder for your body to adjust. (Driving provides a more gradual change.)
- Your age. Young people are more likely to experience altitude sickness. Likewise, older people experience more severe symptoms. But, Dr. Choi clarifies: “Older people experience more severe symptoms, not so much because of their age, but because they have more frequent chronic medical problems and may not adapt to this elevation as well as someone younger,” he says.
“When your body is in this stressful situation with low-oxygen and low-pressure, you have to adapt to it,” says Dr. Choi. “If you’re unable to adapt to a higher elevation, it can cause swelling in different organs. The ones that we worry about the most experience swelling in the brain or lungs.”
Surprisingly having certain underlying health conditions, such as diabetes or asthma doesn’t automatically make you more likely to have issues at higher altitudes.
Things to watch for
If you head to the mountains and do feel the effects of the altitude, chances are likely your symptoms will be mild. Watch for these mild symptoms:
- Shortness of breath.
- Problems sleeping.
You’ll typically experience these symptoms within hours after arriving at a high altitude. Symptoms usually resolve on their own shortly as your body acclimates to the elevation.
“Most people are able to tolerate these mild symptoms and still function and do their activities,” Dr. Choi says. “Symptoms can last from minutes to hours to even days.” Dr. Choi says over-the-counter (OTC) medications should ease symptoms.
If you can’t adjust
In rare cases, you might be unable to acclimate to a high altitude. As a result, symptoms can become more severe and cause complications with your brain or lungs. If you feel confused or disoriented, it might mean the altitude is affecting your brain function.
If you’re having problems breathing, it could indicate you’re having a pulmonary edema, where excess fluid builds up in your lungs. It’s important to seek medical attention right away if you experience any of these symptoms.
Some of the more severe symptoms include:
- Loss of coordination or trouble walking.
- Severe headache that doesn’t improve with OTC medications.
- Tightness or congestion in your chest.
- Cough, sometimes with a pink frothy substance.
Do this if you have symptoms
If you have mild symptoms that last for a few hours, you may be able to control the problem with rest and hydration.
“If your symptoms last longer or seem to get worse, you may need to descend from the high-altitude area,” Dr. Choi says. “If symptoms are severe, such as confusion or trouble walking, you should get to the nearest emergency room immediately. Not only should you descend to a lower altitude, but you may also need oxygen.”
Dr. Choi notes that some people may experience altitude sickness briefly when flying because you ascend very quickly. However, that feeling quickly dissipates because the cabin in the plane is pressurized.
Tips to avoid altitude sickness
The best way to treat altitude sickness is to plan ahead, Dr. Choi says. He recommends the following ways you can limit your risk.
1. Skip the macchiatos and beers
Avoid caffeinated drinks, such as coffee and tea, one day before leaving for your trip. Avoid alcohol before departing for your trip too. And try to avoid them during your trip as well.
“Most people are traveling for fun, but alcohol and caffeinated drinks are things that actually affect our ability to adjust to altitude,” Dr. Choi says. “Also, these drinks don’t actually hydrate you, so it’s another reason to avoid it.”
2. Drink twice as much water
One of the best ways to help your body adjust to high altitude is to drink more water.
High-altitude areas have low humidity which keeps the air dry, so you should drink twice as much water as you’re used to, Dr. Choi says.
Also, eat more carbohydrates. Carbs can reduce acute mountain sickness because they require less oxygen than fats for digestion.
3. Acclimate before heading up
Adjusting to a higher altitude can take a day or two, so if you’re not in any hurry, plan to take it slow and spend a couple nights at an intermediate altitude. This will give your body time to adapt to a lower level of oxygen and pressure. Going to Vail? Stay in Denver overnight before continuing on.
“You want a gradual exposure to that environment rather than a rapid ascent,” Dr. Choi says.
4. Talk to your doctor
If you’re planning a trip to a high-altitude area, talk to your doctor before you go.
This is especially important if high altitudes have bothered you in the past, or you have a chronic medical problem such as lung or heart disease, discuss your concerns ahead of time with your primary care physician.
It’s also wise to find out where the local medical clinics are in case of an emergency. This is your backup plan in case your symptoms worsen. Additionally, Dr. Choi says most hotels in high-altitude areas carry oxygen for emergency situations.
“These are simple things you can do that may help prevent symptoms or at least provide you with a plan in the event something goes wrong,” he says.